Power transmission system and power transmission method

Abstract

This power transmission system includes a power transmission unit and a power reception unit. The power transmission unit, which is provided with a drive circuit including a coil, generates electromagnetic waves, and emits the electromagnetic waves from the coil. The power reception unit comprises a resonator array structure formed by arranging a plurality of resonators that are positioned, relative to the power transmission unit, with a dielectric plate therebetween and are positioned set apart from the dielectric plate. The resonators can resonate with magnetic field components of the electromagnetic waves, and are smaller than the wavelength of the electromagnetic waves. The coil and the first space between the dielectric plate and the first surface of the resonator arrangement structure are coupled by a first coupling generated by a magnetic field, and a first load is connected in series with the first coupling. The magnetic field is transmitted through the first space so that the coil and the resonator array structure are coupled by a second coupling. The resonator array structure and a second space that contacts a second surface of the resonator array structure are coupled by a third coupling generated by the magnetic field, and a second load is connected in series with the third coupling.

Description

Power transmission system and power transmission method

[0001] The present disclosure relates to a power transmission system and a power transmission method.

[0002] The plasma processing apparatus disclosed in Patent Document 1 includes a processing vessel, an electromagnetic wave generator, and a resonator array. The processing vessel provides a processing space. The electromagnetic wave generator generates electromagnetic waves for plasma excitation and is supplied to the processing space. The resonator array is formed by arranging multiple resonators, each of which can resonate with the magnetic field component of the electromagnetic wave and has a size smaller than the wavelength of the electromagnetic wave, and is located within the processing vessel.

[0003] Non-Patent Document 1 states, "Such power transmission efficiency can also be calculated using an equivalent circuit as shown in Fig. 5. For example, when considering inductive coupling, in the case of an external antenna, the induced electric field generated by the antenna current is oriented in the same θ direction as the antenna current, so eddy currents flow in the doughnut-shaped plasma region (thickness is about the skin depth) directly below the antenna. In other words, this coupling is performed by connecting the antenna to the primary winding and the doughnut-shaped plasma to the secondary winding (L ｐ , L ｅ , R ｐ ) can be considered as a transformer coupling. The inductance L of the antenna in the primary winding ａ and resistance R ａ Since is known, the plasma resistance R in the secondary winding ｐ (Considering collisional heating and collisionless statistical heating), the geometric inductance L determined by the shape of the plasma current ｇ , the inertial inductance L of the electron ｅ By calculating the mutual inductance M between the windings and analyzing the equivalent circuit in Fig. 5(a), the power transmission efficiency by inductive coupling ξ ｉ is shown by the thin solid line in Fig. 4(b). On the other hand, the high frequency voltage V applied to the antenna conductor ＲＦ is the capacitance of the dielectric window, C ｄ and sheath capacitance C ｓ Through the plasma resistance R ｓ Therefore, the power transmission efficiency by electrostatic coupling is ｃIt is also disclosed that "the thin dashed line in Fig. 4(b) can be calculated by analyzing the equivalent circuit in Fig. 5(b)."

[0004] International Publication No. 2023 / 032725

[0005] Keiji Nakamura and Hideo Sugai, "Production and Diagnostics of New High-Density Plasmas for Processes III 3. Inductively Coupled Plasmas," Journal of the Society of Plasma and Nuclear Fusion Research, Japan Society of Plasma and Nuclear Fusion Research, February 1998, Vol. 74, No. 2, pp. 155-159

[0006] The present disclosure provides a power transmission system and a power transmission method that can realize stable plasma generation using a resonator array structure.

[0007] A power transfer system according to one aspect of the present disclosure includes a power transmitting unit and a power receiving unit. The power transmitting unit includes a drive circuit including a coil and is configured to generate and radiate electromagnetic waves from the coil. The power receiving unit is disposed between the power transmitting unit and the power transmitting unit via a dielectric plate and spaced apart from the dielectric plate, and is configured to include a resonator array structure formed by an array of multiple resonators that can resonate with a magnetic field component of the electromagnetic waves radiated from the power transmitting unit and have a size smaller than the wavelength of the electromagnetic waves. The coil and a first space between the dielectric plate on which the coil is disposed and a first surface of the resonator array structure are coupled by a first coupling due to a magnetic field, and a first load is connected in series with the first coupling. The coil and the resonator array structure are coupled by a second coupling due to transmission of a magnetic field through the first space. The resonator array structure and a second space adjacent to a second surface opposite the first surface of the resonator array structure are coupled by a third coupling due to a magnetic field, and a second load is connected in series with the third coupling.

[0008] According to the present disclosure, stable plasma generation can be achieved using a resonator array structure.

[0009] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a plasma processing apparatus according to a first embodiment of the present disclosure. FIG. 2 is a plan view showing an example of the configuration of a support member and a resonator array according to the first embodiment, as viewed from above. FIG. 3 is a cross-sectional view showing an example of a cross section of a single resonator in the resonator array according to the first embodiment. FIG. 4 is a plan view showing another example of the configuration of a support member and a resonator array according to the first embodiment, as viewed from above. FIG. 5 is a cross-sectional view showing another example of a cross section of a single resonator in the resonator array according to the first embodiment. FIG. 6 is a diagram showing an example of a circuit model of a power transmission system according to the first embodiment. FIG. 7 is a diagram showing an example of a comparison of power transmission systems. FIG. 8 is a diagram showing an example of a case where a circuit model of multiple resonators is approximated as a circuit model of a resonator array. FIG. 9 is a diagram showing an example of a circuit model of a space S1 and a resonator array. FIG. 10 is a diagram showing an example of a circuit model during plasma generation according to the first embodiment. FIG. 11 is a diagram showing an example of a plasma generation position according to the first embodiment. FIG. 12 is a flowchart showing an example of a process flow of a plasma control process according to the first embodiment. FIG. 13 is a diagram showing an example of a simulation result during plasma ignition according to the first embodiment. FIG. 14 is a diagram showing an example of a simulation result of plasma ignition according to the first embodiment. FIG. 15 is a diagram showing an example of a simulation result of plasma generation according to the first embodiment. FIG. 16 is a diagram showing an example of a simulation result of plasma generation according to the first embodiment. FIG. 17 is a diagram showing an example of a detailed simulation result of plasma ignition according to the first embodiment. FIG. 18 is a schematic cross-sectional view showing an example of a configuration of a plasma processing apparatus according to a second embodiment of the present disclosure. FIG. 19 is a plan view showing an example of a configuration of a support member and a resonator array according to the second embodiment, viewed from above. FIG. 20 is a cross-sectional view showing an example of a cross section of a single resonator in the resonator array according to the second embodiment. FIG. 21 is a plan view showing another example of a configuration of a support member and a resonator array according to the second embodiment, viewed from above. FIG. 22 is a cross-sectional view showing another example of a cross section of a single resonator in the resonator array according to the second embodiment. FIG. 23 is a diagram showing an example of a circuit model of a power transmission system according to the second embodiment.FIG. 24 is a diagram illustrating an example of a comparison of power transmission systems. FIG. 25 is a diagram illustrating an example of approximating a circuit model of a plurality of resonators as a circuit model of a resonator array structure. FIG. 26 is a diagram illustrating an example of a circuit model of the space S1 and the resonator array structure. FIG. 27 is a diagram illustrating an example of a circuit model during plasma generation according to the second embodiment. FIG. 28 is a diagram illustrating an example of a plasma generation position according to the second embodiment. FIG. 29 is a flowchart illustrating an example of a processing flow of a plasma control process according to the second embodiment. FIG. 30 is a diagram illustrating an example of a simulation result during plasma ignition according to the second embodiment. FIG. 31 is a diagram illustrating an example of a simulation result during plasma ignition according to the second embodiment. FIG. 32 is a diagram illustrating an example of a simulation result of plasma generation according to the second embodiment. FIG. 33 is a diagram illustrating an example of a simulation result of plasma generation according to the second embodiment. FIG. 34 is a diagram illustrating an example of a simulation result of plasma generation according to the second embodiment. FIG. 35 is a diagram illustrating an example of a simulation result of plasma generation according to the second embodiment. FIG. 36 is a diagram illustrating an example of a simulation result of plasma generation according to the second embodiment.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a power transmission system and a power transmission method will be described in detail with reference to the accompanying drawings. Note that the disclosed technology is not limited to the following embodiments.

[0011] In a plasma processing apparatus using microwaves for plasma excitation, the power of the microwaves supplied into the processing vessel may be increased to increase the electron density of the plasma. The higher the power of the microwaves supplied into the processing vessel, the higher the electron density of the plasma can be.

[0012] Here, it is known that when the power of the microwaves supplied into the processing vessel is increased and the plasma electron density reaches a certain upper limit, the dielectric constant of the space inside the processing vessel becomes negative. This upper limit of the electron density is appropriately called the "cutoff density." Furthermore, the refractive index is known as an index indicating whether microwaves propagate through space. The refractive index N is expressed by the following formula (1): N = √ε√μ (1) where ε: dielectric constant, μ: magnetic permeability

[0013] Since magnetic permeability is generally positive, when the dielectric constant of the space within the processing vessel becomes negative, the refractive index of the space within the processing vessel becomes a pure imaginary number according to the above formula (1). As a result, microwaves are attenuated and cannot propagate through the space within the processing vessel. When the plasma electron density reaches the cutoff density, microwaves cannot propagate through the space within the processing vessel, and the microwave power is not sufficiently absorbed by the plasma. As a result, there is a problem that the plasma generated within the processing vessel is prevented from densifying over a wide area. While the above description uses microwaves as an example, similar problems also occur in plasma processing apparatuses using electromagnetic waves in the short wave (HF: High Frequency) to ultra-high frequency (UHF) bands.

[0014] Patent Document 1 also describes an example in which a resonator array is disposed in a processing vessel of a plasma processing apparatus at a distance from a dielectric window, and microwaves are supplied into the processing vessel through the dielectric window. The resonator array can make both the permittivity and permeability negative in the plasma generation region by resonating with microwaves through multiple resonators, enabling microwave propagation in the plasma generation region. When surface wave plasma is generated in the space between the dielectric window and the resonator array, microwave propagation is possible as long as the separation distance between the dielectric window and the resonator array is equal to or less than the plasma skin depth (e.g., approximately 20 mm). However, when increasing the plasma density, a short separation distance between the dielectric window and the resonator array (e.g., less than 50 mm) can cause the plasma to become unstable. The separation distance between the dielectric window and the resonator array varies depending on the gas type, pressure, power, and power supply frequency. It is stated that there are no restrictions on the separation distance as long as there is no plasma in the space between the dielectric window and the resonator array and microwaves can propagate to the resonator array.

[0015] Furthermore, Non-Patent Document 1 states that the equivalent circuit of inductively coupled plasma (ICP) can be considered as a transformer coupling with the antenna as the primary winding and the doughnut-shaped plasma directly below the antenna as the secondary winding. In other words, in the equivalent circuit of inductively coupled plasma, the antenna and plasma are inductively coupled. Furthermore, Non-Patent Document 1 also states that ICP antenna types are divided into external antenna types placed outside the vacuum vessel and internal antenna types installed inside the vacuum vessel. It has been shown that the internal antenna type can reduce the antenna current for flowing induced current in the plasma compared to the external antenna type, thereby suppressing Joule loss in the antenna. In other words, it has been shown that the internal antenna type has high power transmission efficiency. However, with internal antennas, the plasma potential increases due to strong inductive coupling and strong electrostatic coupling, resulting in large power loss in the plasma. Here, we will apply the concept of the equivalent circuit in Non-Patent Document 1 to a case where the plasma processing apparatus of Patent Document 1 uses an antenna similar to that for inductively coupled plasma to radiate electromagnetic waves to a resonator array structure.

[0016] If the distance between the dielectric window and the resonator array is short (e.g., less than 50 mm), the coupling with the antenna is weak in the space between the dielectric window and the resonator array, resulting in low-density plasma or no plasma being generated. In this case, if the multiple resonators in the resonator array resonate with the electromagnetic waves radiated from the antenna, the coupling between the antenna and the resonator array becomes strong, and plasma is generated on the processing chamber side of the resonator array, which is opposite the dielectric window side. However, if the distance between the resonator array and the substrate on the processing chamber side is short (e.g., less than 50 mm), the plasma may not be stable.

[0017] On the other hand, if the distance between the dielectric window and the resonator array is long (e.g., 50 mm or more), the space between the dielectric window and the resonator array will be strongly coupled to the antenna, and plasma will be generated along with the dielectric window side of the resonator array that resonates with the electromagnetic waves. If it is desired to supply radicals to the processing chamber, it is conceivable to generate plasma in the space between the dielectric window and the resonator array and use the through-holes in the resonator array as a showerhead to supply radicals to the processing chamber. In this case, stable plasma generation is required in the space between the dielectric window and the resonator array. Therefore, it is expected that stable plasma generation by the resonator array will be achieved even when the resonator array is disposed at a distance from the dielectric window.

[0018] First Embodiment [Configuration of Plasma Processing Apparatus] FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a plasma processing apparatus 1 according to a first embodiment of the present disclosure. The plasma processing apparatus 1 includes an apparatus main body 10 and a control device 11. The apparatus main body 10 includes a processing vessel 12, a stage 14, an RF (Radio Frequency) power supply (an example of an electromagnetic wave generator) 16, a dielectric window 20, an antenna 30, a gas supply unit 38, and a resonator array structure 100. The apparatus main body 10 also includes a central gas inlet unit 13. The central gas inlet unit 13 is disposed above the stage 14 and attached to a central opening of the dielectric window 20. The antenna 30 is disposed above or above (externally of) the processing vessel 12 (dielectric window 20).

[0019] The processing vessel 12 is formed in a substantially cylindrical shape using, for example, aluminum whose surface is anodized, and provides substantially cylindrical spaces S1 and S2 therein. Note that space S1 is an example of a reaction chamber, and space S2 is an example of a processing chamber. The processing vessel 12 is safety grounded. The processing vessel 12 also has a sidewall 12a and a bottom 12b. The central axis of the sidewall 12a is defined as axis Z. The bottom 12b is provided on the lower end side of the sidewall 12a. An exhaust port 12h for exhaust is provided in the bottom 12b. The upper end of the sidewall 12a is open. The inner wall surface of the sidewall 12a faces the spaces S1 and S2. That is, the sidewall 12a is provided with its inner wall surface facing the spaces S1 and S2.

[0020] An opening 12c is formed in the side wall 12a for carrying in and out the substrate WP. The opening 12c is opened and closed by a gate valve G.

[0021] A dielectric window 20 is provided at the upper end of the side wall 12a, and closes the opening at the upper end of the side wall 12a from above. A lower surface 20a of the dielectric window 20 faces the space S1. That is, the dielectric window 20 is provided with its lower surface 20a facing the space S1.

[0022] The stage 14 is accommodated in the processing vessel 12. The stage 14 is disposed so as to face the resonator array structure 100, which also serves as a shower head, in the direction of the axis Z. The space between the stage 14 and the resonator array structure 100 is a space S2. A substrate WP is placed on the stage 14.

[0023] The stage 14 includes a base 14 a and an electrostatic chuck 14 c. The base 14 a is made of a conductive material such as aluminum and has a generally disk-like shape. The base 14 a is disposed in the processing chamber 12 such that the central axis of the base 14 a substantially coincides with the axis Z.

[0024] The base 14a is supported by a cylindrical support 48 made of an insulating material and extending in the Z-axis direction. A conductive cylindrical support 50 is provided on the outer periphery of the cylindrical support 48. The cylindrical support 50 extends from the bottom 12b of the processing vessel 12 toward the dielectric window 20 along the outer periphery of the cylindrical support 48. An annular exhaust path 51 is formed between the cylindrical support 50 and the sidewall 12a. The stage 14 may be configured to be movable in the vertical direction (Z-axis direction) by a drive mechanism (not shown), thereby changing the distance between the lower surface of the resonator array 100 and the upper surface of the electrostatic chuck 14c. This allows adjustment of the energy level by residence time.

[0025] An annular baffle plate 52 having a plurality of through holes formed in the thickness direction is provided above the exhaust path 51. The above-mentioned exhaust port 12h is provided below the baffle plate 52. An exhaust device 56 having a vacuum pump such as a turbomolecular pump, an automatic pressure control valve, etc. is connected to the exhaust port 12h via an exhaust pipe 54. The exhaust device 56 can reduce the pressure in the spaces S1 and S2 to a desired vacuum level.

[0026] The base 14a functions as a radio-frequency electrode. A radio-frequency power supply 58 for RF bias is electrically connected to the base 14a via a power feed rod 62 and a matching unit 60. The radio-frequency power supply 58 supplies, via the matching unit 60 and the power feed rod 62, to the base 14a, bias power of a predetermined frequency (e.g., 13.56 MHz) suitable for controlling the energy of ions attracted to the substrate WP.

[0027] The matching unit 60 houses a matcher for matching the impedance on the high frequency power supply 58 side with the impedance on the load side, mainly consisting of the electrodes, plasma, and processing chamber 12. The matcher includes a blocking capacitor for generating a self-bias. If an RF bias is not used, the high frequency power supply 58, matching unit 60, and power feed rod 62 may be omitted.

[0028] An electrostatic chuck 14c is provided on the upper surface of the base 14a. The electrostatic chuck 14c attracts and holds the substrate WP by electrostatic force. The electrostatic chuck 14c has a substantially disc-shaped outer shape and includes an electrode 14d, an insulating film (dielectric film) 14e, and an insulating film (dielectric film) 14f. The electrostatic chuck 14c is disposed on the upper surface of the base 14a so that the central axis of the electrostatic chuck 14c substantially coincides with the axis Z. The electrode 14d of the electrostatic chuck 14c is formed of a conductive film and is provided between the insulating films 14e and 14f. A DC power supply 64 is electrically connected to the electrode 14d via a coated wire 68 and a switch 66. The electrostatic chuck 14c attracts and holds the substrate WP on its upper surface by electrostatic force generated by a DC voltage applied from the DC power supply 64. The upper surface of the electrostatic chuck 14c is a support surface on which the substrate WP is placed and faces the space S2. That is, the electrostatic chuck 14c is provided with its upper surface, which is its mounting surface, facing the space S2. An edge ring 14b is provided on the base 14a. The edge ring 14b is arranged to surround the substrate WP and the electrostatic chuck 14c. The edge ring 14b is also called a focus ring.

[0029] A flow path 14g is provided inside the base 14a. A coolant is supplied to the flow path 14g from a chiller unit (not shown) via a pipe 70. The coolant supplied to the flow path 14g is returned to the chiller unit via a pipe 72. The coolant, the temperature of which is controlled by the chiller unit, circulates through the flow path 14g of the base 14a, thereby controlling the temperature of the base 14a. By controlling the temperature of the base 14a, the temperature of the substrate WP on the electrostatic chuck 14c on the base 14a is controlled via the electrostatic chuck 14c on the base 14a.

[0030] Furthermore, the stage 14 is provided with a pipe 74 for supplying a heat transfer gas such as He gas between the upper surface of the electrostatic chuck 14c and the rear surface of the substrate WP.

[0031] The RF power supply 16 is coupled to the antenna 30 and configured to generate a source RF signal (source RF power) for plasma generation via at least one impedance matching circuit. In one embodiment, the source RF signal has a frequency within a range of 3 MHz to 3000 MHz. In one embodiment, the RF power supply 16 may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to the antenna 30. As described above, the RF power supply 16 is an example of an electromagnetic wave generator and an example of a high-frequency power supply. The antenna 30 is also an example of an electromagnetic wave supply unit.

[0032] The antenna 30 includes one or more coils. In one embodiment, the antenna 30 may include an outer coil and an inner coil arranged coaxially. In this case, the RF power supply 16 may be connected to both the outer coil and the inner coil, or to either the outer coil or the inner coil. In the former case, the same RF generator within the RF power supply 16 may be connected to both the outer coil and the inner coil, or separate RF generators may be connected to the outer coil and the inner coil separately. In one embodiment, the antenna 30 is a planar coil formed in a substantially circular spiral shape (planar spiral shape). In other words, the antenna 30 is wound in a loop shape. Note that the magnetic field generated by the antenna 30 is oriented along the axis Z. The opening of the antenna 30 may have any shape, such as a circle, an ellipse, or a polygon (e.g., a square, a triangle, etc.). Note that the RF power supply 16 and the antenna 30 are an example of a power transmission unit equipped with a drive circuit including a coil and configured to generate and radiate electromagnetic waves from the coil. The antenna 30 also supplies a magnetic field component perpendicular to a plane on which a plurality of resonators 101 (described later) are arranged.

[0033] Furthermore, when the antenna 30 includes an outer coil and an inner coil, the outer coil functions as a primary coil connected to the RF power supply 16. In one embodiment, the outer coil is a planar coil formed in a substantially circular spiral shape. The inner coil functions as a secondary coil inductively coupled to the primary coil. In other words, the inner coil is not connected to the RF power supply 16. In one embodiment, the inner coil is a planar coil formed in a substantially circular ring shape. In one embodiment, the inner coil is connected to a variable capacitor, and the direction and magnitude of the current flowing through the inner coil are controlled by controlling the capacitance of the variable capacitor. The outer coil and the inner coil may be disposed at the same height or at different heights. In one embodiment, the inner coil is disposed at a lower position than the outer coil.

[0034] The gas inlet is configured to introduce at least one process gas from the gas supply unit 38 into the space S1. In one embodiment, the gas inlet includes a center gas injector (CGI) 13. The center gas injector 13 is disposed above the stage 14 and the resonator array 100 and attached to a central opening formed in the dielectric window 20. The center gas injector 13 has at least one gas supply port 13a, at least one gas flow path 13b, and at least one gas inlet port 13c. The process gas supplied to the gas supply port 13a passes through the gas flow path 13b and is introduced into the space S1 from the gas inlet port 13c. The process gas is excited by electromagnetic waves supplied from the antenna 30 to the space S1 via the dielectric window 20 and the resonator array 100. This converts the process gas into plasma in the space S1, and radicals and unactivated process gas contained in the plasma are supplied to the space S2 through through-holes 118 and 133, which will be described later. Furthermore, ions contained in the plasma recombine to form radicals as they pass through the through holes 118, 133, and these radicals are similarly supplied to the space S2. The space S2 becomes a high-density radical region, and the substrate WP is processed by the radicals. Note that the gas introduction part may include, in addition to or instead of the central gas injection part 13, one or more side gas injection parts (SGIs) attached to one or more openings formed in the side wall 12 a.

[0035] The gas supply 38 may include at least one gas source 38a and at least one flow controller 38b. In one embodiment, the gas supply 38 is configured to supply at least one process gas from a corresponding gas source 38a to the gas inlet via a corresponding flow controller 38b. Each flow controller 38b may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 38 may include one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0036] The resonator array 100 is formed by arranging a plurality of resonators that can resonate with the magnetic field component of the electromagnetic wave and that are smaller in size than the wavelength of the electromagnetic wave, and is located, for example, above the opening 12c in the processing vessel 12 while being supported by a support member 22. The resonator array 100 also includes a through-hole 118 (described later) that separates the space S1 from the space S2 and communicates the space S1 with the space S2. In other words, the resonator array 100 is an example of a showerhead that includes the through-hole 118. The support member 22 may also have a sealing structure that seals the space S1 from the space S2.

[0037] Here, the separation distance between the space S1 and the space S2 is defined as follows: Ｓ１ is the distance between the lower surface 20a of the dielectric window 20 and the upper surface of the resonator array 100 (the surface opposite to the lower surface 20a). Ｓ２ is the distance between the bottom surface of the resonator array 100 (the surface facing the top surface of the substrate WP) and the top surface of the substrate WP. The top surface of the resonator array 100 is also referred to as the first surface of the resonator array 100, and the bottom surface of the resonator array 100 is also referred to as the second surface of the resonator array 100. Furthermore, the distance between the top and bottom surfaces of the resonator array 100, i.e., the thickness of the resonator array 100, is referred to as thickness δ ｔ Let's say.

[0038] In the plasma processing apparatus 1 of the first embodiment, the separation distance δ between the dielectric window 20 and the resonator array structure 100 is Ｓ１ This is an example where the separation distance δ is less than a specific value. Ｓ１ In other words, in the first embodiment, the distance between the lower surface 20a of the dielectric window (top panel) 20 and the first surface of the resonator array structure 100 (separation distance δ Ｓ１) is less than 50 mm. In this case, the space S1 between the dielectric window 20 and the resonator array 100 has a weaker coupling with the antenna 30. On the other hand, the resonator array 100 has a stronger coupling with the antenna 30, and plasma is generated in the space S2 between the resonator array 100 and the substrate WP, along with the second surface side of the resonator array 100 that resonates with the electromagnetic wave. Note that the bulk of the resonator array 100 that resonates with the electromagnetic wave has a negative magnetic permeability. In other words, the resonator array 100 is formed so that the overall magnetic permeability is negative. Furthermore, the separation distance δ of the space S2 Ｓ２ is a distance greater than or equal to a specific value. Ｓ２ A specific value of the separation distance δ is, for example, 50 mm. Ｓ２ By setting the distance to a specific value or more, the stability of the plasma generated in the space S2 can be improved.

[0039] That is, by positioning the resonator array 100 within the processing vessel 12, the electromagnetic waves supplied to the space S1 by the antenna 30 can resonate with the multiple resonators of the resonator array 100. Resonance between the electromagnetic waves and the multiple resonators allows the electromagnetic waves to be efficiently supplied to the space S2 within the processing vessel 12 and the magnetic permeability of the space S2 to be negative. When the magnetic permeability of the space S2 is negative, even if the electron density of the plasma generated in the space S2 reaches the cutoff density and the dielectric constant of the space S2 is negative, the refractive index becomes a real number according to the above formula (1), allowing the electromagnetic waves to propagate in the space S2. As a result, even if the electron density of the plasma generated in the space S2 reaches the cutoff density, the electromagnetic waves can propagate beyond the skin depth of the plasma, and the power of the electromagnetic waves is efficiently absorbed by the plasma. As a result, high-density plasma can be generated over a wide area beyond the skin depth of the plasma. That is, the plasma processing apparatus 1 according to the first embodiment can stabilize the plasma in the space S2 and achieve high density over a wide area.

[0040] Here, the detailed configuration of the resonator array 100 will be described with reference to Figures 1 and 2. Figure 2 is a plan view showing an example of the configuration of the support member 22 and the resonator array 100 according to the first embodiment, as viewed from above. In Figure 2, the support member 22 and the resonator array 100 are shown in a disk shape.

[0041] The resonator array 100 is formed, for example, by arranging a plurality of resonators 101 such that their longitudinal directions extend along radial lines from the center of the resonator array 100. For example, the resonator array 100 has two resonators 101 arranged along each of eight radial lines spaced at 45-degree intervals. The resonators 101 are arranged such that their coils 111 face the center of the resonator array 100 and that the coils 111 of the outer resonators 101 are adjacent to the capacitors 112 of the inner resonators 101. That is, the inner resonators 101 are arranged at equal intervals on a first circle, and the outer resonators 101 are arranged at equal intervals on a second circle. The resonators 101 are integrally formed as the resonator array 100. The resonators 101 may be formed separately and fitted into a radial frame or bonded to each other to form the resonator array 100. The substrate WP facing the resonator array 100 is preferably disposed in a region where the coils 111 of the resonators 101 arranged on the outside in the direction of the axis Z in Fig. 1 are present. In the following description, the resonator array 100 may be referred to as a metamaterial, and each of the resonators 101 may be referred to as a metaatom.

[0042] Fig. 3 is a cross-sectional view showing an example of a cross section of a single resonator in the resonator array structure according to the first embodiment. Fig. 3 shows a cross section of a single resonator 101 in the array direction (the direction of radial lines from the center of the resonator array structure 100), using one of the multiple resonators 101 shown in Fig. 2 as an example. The single resonator 101 has a series resonant circuit consisting of a coil 111 and a capacitor 112, surrounded by a dielectric 115. The magnetic field generated by the antenna 30 is directed through the coil 111.

[0043] In the resonator 101, electrodes 116 and 117 of the capacitor 112 sandwich a dielectric 115a, which is a plate-shaped region inside the dielectric 115. A coil 111 is formed on the upper surface of the dielectric 115a, on which the electrode 116 is formed. The coil 111 is, for example, a circular flat spiral coil with three turns, and one end is connected to the electrode 116 via a lead portion 113. The other end of the coil 111 penetrates the dielectric 115a via a through hole 114, appears on the lower surface of the dielectric 115a, on which the electrode 117 is formed, and is connected to the electrode 117 via the lead portion 113. That is, from the perspective of lamination, the resonator 101 has a single-layered circular flat spiral coil as the coil 111, and a single-layered dielectric as the capacitor 112. As a result, the resonator 101 can form a series resonant circuit with the three-turned circular flat spiral coil 111 and the capacitor 112, which has two-layered electrodes. That is, the resonator 101 is an example of a resonator in which the series resonant circuit is a lumped constant circuit.

[0044] Furthermore, a through-hole 118 is provided at the center of the coil 111. The through-hole 118 connects the upper space S1 of the resonator array 100 with the lower space S2. That is, the resonator array 100 has the through-hole 118 penetrating from the upper surface to the lower surface. In other words, the resonator array 100 has the through-hole 118 penetrating from the first surface to the second surface opposite the first surface. The through-hole 118 has, for example, a circular cross section. The through-hole 118 serves as, for example, a path through which plasma ignited in the space S1 propagates to the space S2. The through-hole 118 also allows a process gas to pass from the space S1 to the space S2. That is, the process gas is supplied from the space S1 to the space S2, and the plasma ignited in the space S1 propagates to the space S2 through the through-hole 118. In the space S2, plasma is stably generated due to the resonance of the resonator array 100. The space S2 becomes a high-density plasma region containing radicals and ions, and the substrate WP is processed by the plasma.

[0045] The resonator array structure 100 is composed of an array structure of a plurality of resonators 101, and each of the plurality of resonators 101 has a relatively small area compared to the antenna 30 and the substrate WP. Therefore, the resonator array structure 100 can reduce loss compared to loss caused by electrostatic induction in an internal antenna of an ICP.

[0046] Furthermore, the resonator array 100 may use resonators of distributed constant circuits as the resonators 101. Fig. 4 is a plan view showing another example of the configuration of the support member and the resonator array according to the first embodiment as viewed from above.

[0047] The resonator array 100a shown in FIG. 4 is formed by arranging a plurality of resonators 121, each of which can resonate with the magnetic field component of an electromagnetic wave and has a size smaller than the wavelength of the electromagnetic wave, in a lattice pattern. Specifically, as shown in FIG. 4, the plurality of resonators 121 are arranged in a plane parallel to the lower surface 20a of the dielectric window 20 in the flat resonator array 100a. That is, when viewed from the lower surface 20a, the C-shaped ring members 131, which are shown transparently, are arranged in a lattice pattern so that the C shape is visible. The resonator array 100a has, for example, eight rows and eight columns of resonators 121 arranged. In this case, the boundaries between the plurality of resonators 121 are shown as boundaries 125, but in reality, the plurality of resonators 121 are integrally formed as the resonator array 100a. Note that the plurality of resonators 121 may be formed separately and then fitted into a lattice frame or bonded to each other to form the resonator array 100a. Each of the multiple resonators 121 forms a series resonant circuit consisting of a capacitor equivalent element and a coil equivalent element. The series resonant circuit is realized by patterning a conductor on a plane. The magnetic field generated by the antenna 30 is directed to pass through the C-shaped ring member 131.

[0048] FIG. 5 is a cross-sectional view showing another example of a cross section of a single resonator in the resonator array according to the first embodiment. FIG. 5 shows a cross section of a single resonator 121, using one resonator 121 as an example among a plurality of resonators 121 formed integrally. As shown in FIGS. 4 and 5 , the single resonator 121 is located within a region surrounded by a boundary 125. That is, in the example shown in FIGS. 4 and 5 , the resonator 121 has two C-shaped ring members 131 each surrounded by a dielectric 132. The dielectric 132 may be formed such that the thickness from the first C-shaped ring member 131 to the first surface 122 is thinner than the thickness from the second C-shaped ring member 131 to the second surface 123 on the side where plasma is generated.

[0049] The through-hole 133 communicates between the space S1 and the space S2. The through-hole 133 has, for example, a circular cross section. Like the through-hole 118 of the resonator 101 in the resonator array structure 100, the through-hole 133 serves as a path for the plasma ignited in the space S1 to propagate to the space S2, and also allows the process gas to pass from the space S1 to the space S2.

[0050] Referring again to Figure 1, the control device 11 has a processor, a memory, and an input / output interface. The memory stores programs, process recipes, and the like. The processor reads and executes the programs from the memory, thereby controlling each part of the device main body 10 via the input / output interface based on the process recipes stored in the memory.

[0051] For example, when plasma is generated in the spaces S1 and S2, the control device 11 controls the plurality of resonators 101 so that the electromagnetic waves supplied to the spaces S1 and S2 by the antenna 30 resonate with the plurality of resonators 101 in a target frequency band higher than the resonant frequency fr of the plurality of resonators 101. Here, the resonant frequency fr is, for example, a transmission characteristic value (e.g., S ２１ This is the frequency at which the minimum value of

[0052] When the frequency of the electromagnetic waves supplied to the spaces S1 and S2 by the antenna 30 matches the resonance frequency fr (for example, about 68 MHz) of the plurality of resonators 101, ２１ The value of ℓ becomes a minimum value, and resonance occurs between the electromagnetic wave and the multiple resonators 101. The resonance between the electromagnetic wave and the multiple resonators 101 is maintained even in a predetermined frequency band (e.g., approximately 2.4 MHz) higher than the resonant frequency fr of the multiple resonators 101. In the predetermined frequency band higher than the resonant frequency fr of the multiple resonators 101, the resonance between the electromagnetic wave and the multiple resonators 101 can make both the permittivity and permeability of the spaces S1 and S2 negative. Therefore, as can be seen from the above equation (1), propagation of the electromagnetic wave in the spaces S1 and S2 is possible. The target frequency band in the first embodiment is set to a predetermined frequency band (e.g., approximately 2.4 MHz) higher than the resonant frequency fr of the multiple resonators 101. The target frequency band is preferably, for example, within 0.05 times the resonant frequency fr of the multiple resonators 101.

[0053] Regarding the propagation of electromagnetic waves through a plurality of resonators, the relationship between the resonant frequency and the refractive index, the permittivity, and the magnetic permeability has been reported by D. R. Smith, D. C. Vier, Th. Koschny, and C. M. Soukoulis et al. in "Electromagnetic parameter retrieval from inhomogeneous metamaterials" in "PHYSICAL REVIEW E 71, 036617 (2005)," for example.

[0054] In this way, by resonating the electromagnetic wave with the multiple resonators 101 in a target frequency band higher than the resonant frequency fr of the multiple resonators 101, the electromagnetic wave can propagate beyond the skin depth of the plasma even when the plasma electron density reaches the cutoff density. Therefore, the power of the electromagnetic wave can be efficiently absorbed by the plasma. As a result, high-density plasma can be generated over a wide area beyond the skin depth of the plasma. That is, according to the plasma processing apparatus 1 of the first embodiment, by resonating the electromagnetic wave with the multiple resonators 101 in a target frequency band higher than the resonant frequency fr of the multiple resonators 101, high-density plasma can be achieved over a wide area.

[0055] [Circuit Model of Power Transmission System] Next, a circuit model of the power transmission system will be described using FIGS. 6 to 8 . FIG. 6 is a diagram showing an example of the circuit model of the power transmission system according to the first embodiment. As shown in FIG. 6 , the circuit model of the power transmission system 170 corresponding to the plasma processing apparatus 1 is composed of a power transmitting unit 170a and a power receiving unit 170b. The power transmitting unit 170a includes an RF power supply 16, a matching box 16d, and an antenna 30. The power receiving unit 170b includes a resonator array 100. The antenna 30 and the resonator array 100 are disposed opposite each other via a dielectric window 20 and a space S1. That is, the power receiving unit 170b is disposed between the power transmitting unit 170a and the power transmitting unit 170a and separated from the dielectric window 20, and is configured to include the resonator array 100 formed by arranging a plurality of resonators 101 that can resonate with the magnetic field component of the electromagnetic wave radiated from the power transmitting unit 170a and that are smaller in size than the wavelength of the electromagnetic wave. The resonator array structure 100 in FIG. 6 is shown schematically as a plurality of resonators 101 each having a coil and a capacitor.

[0056] In the circuit model, the RF power supply 16 includes, for example, an alternating current (AC)-direct current (DC) converter 16a, a DC-DC converter 16b, and an inverter 16c. The AC-DC converter 16a converts AC from a commercial power source or the like into DC and outputs the DC to the DC-DC converter 16b. The DC-DC converter 16b converts the DC input from the DC-DC converter 16b into DC of a voltage required by the inverter 16c and outputs the DC to the inverter 16c. The inverter 16c generates a source RF signal from the input DC and outputs it to the antenna 30 via a matching device 16d. The source RF signal has a frequency within a range of 3 MHz to 3000 MHz. When the resonator array structure 100 is used, the resonators 101 are lumped constant circuit resonators, so the frequency of the source RF signal is 300 MHz or less, for example, 13.56 MHz, 27.12 MHz, 40.68 MHz, 60 MHz, or 68 MHz.

[0057] The matching circuit 16d has, for example, a variable capacitor, and matches (impedance matches) the output of the inverter 16c and the input of the antenna 30. The matching circuit 16d may be an inverted-L or Π-type matching circuit. When power is supplied to the resonator array 100 by magnetic field resonance coupling, the matching circuit 16d may function as a resonant capacitor that configures an LC resonant circuit together with the antenna 30. When power is supplied to the resonator array 100 by electromagnetic phase-modulating coupling (magnetic field phase-modulating coupling), the matching circuit 16d may function as a matching circuit that performs matching, rather than as a resonant capacitor.

[0058] The antenna 30 and the resonator array structure 100 are coupled by a magnetic field H generated by the antenna 30. The magnetic field H generated by the antenna 30 is supplied to penetrate the coils 111 of the multiple resonators 101 of the resonator array structure 100 via the dielectric window 20 and the space S1. The multiple resonators 101 of the resonator array structure 100 resonate due to the magnetic field H, thereby exciting plasma in the space S1 and / or the space S2.

[0059] Here, the power transmission system of the first embodiment will be compared with a general wireless power supply system. Fig. 7 is a diagram showing an example of a comparison of power transmission systems. Fig. 7 shows a schematic comparison between a general wireless power supply system 150 and a power transmission system 170 of the first embodiment. In both the wireless power supply system 150 and the power transmission system 170, a power transmitting side 171 and a power receiving side 172 are coupled by a magnetic field via space.

[0060] In the wireless power supply system 150, a DC power supply 151, a DC-DC converter 152, an inverter 153, a matching box 154, and a power transmission coil 155 are provided on a power transmission side 171. In addition, in the wireless power supply system 150, a power reception coil 156, a rectifier 157, a smoothing capacitor 158, a DC-DC converter 159, and a load 160 are provided on a power reception side 172. The start and end of power supply are controlled by wireless communication between the DC-DC converter 152 and the inverter 153 on the power transmission side 171 and the DC-DC converter 159 on the power reception side 172 by a control unit (not shown). There is a mutual inductance M ｇ１ are joined with

[0061] The power transmission system 170 is provided on a power transmission side 171 with an AC-DC converter 16a, a DC-DC converter 16b, an inverter 16c, a matching device 16d, and an antenna 30. The power transmission system 170 is also provided on a power receiving side 172 with a resonator array structure 100. There is a mutual inductance M ｇ２ Furthermore, there is a mutual inductance M between the resonator array structure 100 and the plasma P excited in the space S1 and / or the space S2. ｇ３ As will be described later, the antenna 30 and the space S1 (including when the plasma P is excited) are also coupled by mutual inductance. That is, the power transmitting unit 170a is disposed on the atmospheric space side, which is outside the processing vessel 12 that provides the processing space. The dielectric plate (dielectric window 20) is the top plate of the processing vessel 12. The power receiving unit 170b is disposed inside the processing space so as to be spaced apart from the top plate.

[0062] When the wireless power supply system 150 is compared with the power transmission system 170, the power transmission side 171 has a structure in which the DC power source 151 to the power transmission coil 155 correspond to the AC-DC converter 16a to the antenna 30, respectively. On the power receiving side 172, in the wireless power supply system 150, the power received by the power receiving coil 156 is converted to DC and supplied to the load 160, whereas in the power transmission system 170, the power received by the resonator array structure 100 is supplied to the plasma P without being converted to DC. In other words, the power transmission system 170 uses magnetic field coupling (M ｇ３ ) supplies a source RF signal to a load, the plasma P.

[0063] 8 is a diagram showing an example of a case where a circuit model of a plurality of resonators is approximated as a circuit model of a resonator array structure. FIG. 8 shows a more detailed circuit model from the antenna 30 to the plasma P of the power transmission system 170 of FIG. 7. Note that the mutual inductance M ｇ２ In FIG. 8, the mutual inductance M ａ , M ａ１ ~M ａｎ In addition, the mutual inductance M ｇ３ In FIG. 8, the mutual inductance M ｂ , M ｂ１ ~M ｂｎ 8, the resonator array structure 100 is represented as a circuit model of a plurality of resonators 101-1, ..., resonator 101-n, and the corresponding plurality of plasmas are represented as circuit models of plasmas P-1, ..., plasma P-n. For example, the resonator 101-1 has a mutual inductance M ａ１ and the mutual inductance M ｂ１ The impedance of the plasma is the impedance Z ｐ１ , ..., impedance Z ｐｎ The details of the circuit model of the plurality of resonators 101 and the corresponding plurality of plasmas are the same as those of the circuit model 181, and therefore will not be described here.

[0064] In the circuit model 180, the resonators 101-1, ..., 101-n have the same characteristics, and therefore can be approximated by a circuit model 181 using one resonator array structure 100. The resonator array structure 100 of the circuit model 181 has an inductance L ｍ１ , L ｍ２ , wiring resistance R ｍ and capacitance C ｍ are connected in series to form a series resonant circuit. ｍ is the geometric inductance L determined by the shape of the plasma current ｇｍ , and the plasma impedance Z ｐｍ are connected in series. Furthermore, the antenna 30 and the inductance L ｍ１ The mutual inductance between ａ and the inductance L ｍ２ and the geometric inductance L ｇｍ The mutual inductance between ｂ When a current flows through the antenna 30, the mutual inductance M ａ A current I flows through the resonator array structure 100 coupled by ｍ flows, and the resonator array structure 100 and the mutual inductance M ｂ The plasma P is bound by ｍ In the equivalent circuit of ｐｍ Here, by controlling the magnetic permeability μ and permittivity ε of the plasma through the LC resonance of the resonator array structure 100, the plasma P ｍ Impedance Z ｐｍ In other words, it is found that it is difficult to control the magnetic permeability μ and the dielectric constant ε of the plasma in a conventional ICP that does not use the resonator array structure 100.

[0065] [Circuit Model of Spaces S1, S2 and Resonator Array 100] Next, a circuit model of the spaces S1, S2 and the resonator array 100 will be described with reference to Fig. 9 to Fig. 11. Fig. 9 is a diagram showing an example of a circuit model of the space S1 and the resonator array. The circuit model 182 shown in Fig. 9 is a circuit model including the RF power supply 16, the matching box 16d, the antenna 30, the space S1 in the internal space of the processing vessel 12, and the resonator array 100.

[0066] In the circuit model 182, the RF power supply 16, the matching device 16d, and the antenna 30 are connected in series as a power transmission circuit. The RF power supply 16 includes an AC-DC converter 16a, a DC-DC converter 16b, and an inverter 16c. The antenna 30 has an inductance L ａ and resistor R ａ In the circuit model 182, the plasma P Ｓ１ (The doughnut-shaped plasma P described later Ｓ１ ) is generated, and the inductance L ｐ and impedance Z ｐ The inductance L of the space S1 is ｐ is the inductance L of the antenna 30 ａ In the circuit model 182, similarly to the circuit model 181, the inductance L ｍ１ is the inductance L of the antenna 30 ａ In the circuit model 182, similarly to the circuit model 181, the inductance L ｍ２ is Plasma P ｍ (Plasma P using metamaterials, which will be described later) ｍ ) geometric inductance L ｇｍ The mutual inductance M2 is the mutual inductance M ａ The mutual inductance M3 corresponds to the mutual inductance M ｂ Corresponds to.

[0067] In other words, the antenna 30 (coil) and the space S1 (first space) between the dielectric window 20 (dielectric plate) on which the antenna 30 is arranged and the upper surface (first surface) of the resonator array structure 100 are coupled by a first coupling (mutual inductance M1) due to a magnetic field, and a first load (impedance Z ｐ ) is connected. The antenna 30 and the resonator array structure 100 are coupled by a second coupling (mutual inductance M2) due to the transmission of a magnetic field through the space S1 (first space). The resonator array structure 100 and the space S2 (second space) in contact with the second surface opposite to the first surface of the resonator array structure 100 are coupled by a third coupling (mutual inductance M3) due to the magnetic field, and a second load (impedance Z ｐｍ ) are connected. The first coupling and the second coupling are coupled in parallel. Furthermore, the first load and the second load are plasma.

[0068] 10 is a diagram showing an example of a circuit model at the time of plasma generation according to the first embodiment. FIG. 11 is a diagram showing an example of a plasma generation position according to the first embodiment. The circuit model 183 shown in FIG. 10 is a circuit model 183 at the time of plasma generation according to the first embodiment. Ｓ１ 1 is a circuit model in which, when the distance S1 is short (for example, less than 50 mm), the coupling between the space S1 and the antenna 30 becomes weaker, and the coupling between the resonator array structure 100 and the antenna 30 becomes stronger. In other words, the circuit model 183 is a case in which the mutual inductance M2 is greater than the mutual inductance M1. That is, the second coupling (mutual inductance M2) is stronger than the first coupling (mutual inductance M1).

[0069] As shown in the circuit model 183 and the plasma generation example 184 of Fig. 11, the antenna 30 corresponds to the external coil of the ICP coil in terms of positional relationship, and transmits electromagnetic waves to the resonator array structure 100. The resonator array structure 100 corresponds to the internal coil of an internal antenna type ICP coil. A source RF signal is supplied to the antenna 30 from the RF power supply 16 via the matching box 16d, so that the antenna 30 and the space S1 directly below the dielectric window 20 resonate, and a resonant current I flows in the antenna 30. ＲＦis playing.

[0070] When plasma is generated, a sheath is generated in the dielectric window 20 and the resonator array 100. The space S1 between the dielectric window 20 and the resonator array 100 is a distance δ Ｓ１ is not sufficient for the thickness of the sheath, the coupling is weak and the doughnut-shaped plasma is not generated directly below the dielectric window 20, resulting in a weak plasma P Ｓ１ is generated, or no plasma is generated. Since no doughnut-shaped plasma is generated in the space S1, the electromagnetic waves propagate within the processing vessel 12. When the resonant frequencies of the multiple resonators 101 in the resonator array structure 100 match the frequency of the source RF signal, the multiple resonators 101 in the resonator array structure 100 resonate. At this time, the control device 11 controls the power and power supply frequency of the RF power supply 16 (drive circuit) so that the second coupling (mutual inductance M2) becomes magnetic field resonance coupling. When the multiple resonators 101 in the resonator array structure 100 resonate, plasma P ｍ As shown in FIG. 11, in the space S2, a plasma P ｍ Thus, a metamaterial plasma (plasma P) is generated. That is, in the space S2, a metamaterial plasma (plasma P) that is a high-density plasma is generated. The metamaterial plasma is a plasma that includes the plasma (plasma metamaterial state) generated in the resonator array 100. Furthermore, when the plasma is ignited, it is ignited on the space S1 side directly below the dielectric window 20, so that damage to the substrate WP when the plasma is ignited can be suppressed. The resonator array 100 also functions as a metamaterial screen that converges the magnetic field H.

[0071] The metamaterial plasma (plasma P) transforms the space S2 into a high-density plasma region, and the substrate WP is processed by this high-density plasma (ions and radicals). Furthermore, the resonator array 100 serves as a plasma source and a showerhead, making it possible to increase the plasma density and improve energy efficiency (plasma input energy / supply energy). Furthermore, the resonator array 100, which serves as the plasma source, can be brought closer to the substrate WP, making it possible to control the high-density plasma by the position of the resonator array 100 (the arrangement of the multiple resonators 101). In other words, in the first embodiment, in plasma (ion and radical) processing, it is possible to improve the in-plane uniformity of the substrate WP while suppressing plasma diffusion directly above the substrate WP.

[0072] [Plasma Control Process] Next, an example of a plasma control process using the plasma processing apparatus 1 according to the first embodiment will be described. Fig. 12 is a flowchart showing an example of the process flow of the plasma control process according to the first embodiment. The plasma control process shown in Fig. 12 is realized by the control device 11 controlling each part of the apparatus main body 10.

[0073] First, the substrate WP is loaded into the processing vessel 12 and placed on the electrostatic chuck 14c (step S101). Then, the control device 11 opens the valve of the gas source 38a and controls the flow rate controller 38b so that a predetermined flow rate of the processing gas is supplied into the processing vessel 12. Then, the control device 11 controls the exhaust device 56 to adjust the pressure inside the processing vessel 12 (step S102).

[0074] Next, the control device 11 controls the RF power supply 16 to supply electromagnetic waves from the antenna 30 to the spaces S1 and S2 within the processing vessel 12 (step S103). Furthermore, when supplying electromagnetic waves to the spaces S1 and S2, the control device 11 controls the power and power supply frequency of the RF power supply 16 so that the second coupling (mutual inductance M2) becomes magnetic resonance coupling. This generates plasma of the processing gas within the processing vessel 12. At this time, it is assumed that the electron density of the plasma reaches the cutoff density. When the electron density of the plasma reaches the cutoff density, electromagnetic waves cannot propagate within the space S2 within the processing vessel 12.

[0075] Therefore, the control device 11 controls the RF power supply 16 to adjust the frequency of the electromagnetic waves supplied from the antenna 30 to the spaces S1 and S2 within the processing vessel 12 to a frequency within a target frequency band (step S104). This generates resonance between the electromagnetic waves and the multiple resonators 101, making both the permittivity and permeability of the plasma in the spaces S1 and S2 negative. As can be seen from the above equation (1), this enables the electromagnetic waves to propagate through the spaces S1 and S2. As a result, the electromagnetic waves can propagate beyond the plasma skin depth in the spaces S1 and S2 within the processing vessel 12, allowing the electromagnetic wave power to be efficiently injected into the plasma, resulting in the generation of high-density plasma over a wide area beyond the plasma skin depth. The power supply frequency in step S103 may be set to a frequency within a target frequency band that results in a negative refractive index.

[0076] Then, in the processing vessel 12, the processing gas is supplied from the space S1 to the space S2, and the plasma ignited in the space S1 propagates to the space S2 through the through-hole 118. In the space S2, the plasma is stably generated by the resonance of the resonator array structure 100. The space S2 becomes a high-density plasma region, and the plasma processing process is performed on the substrate WP using the plasma (step S105). Examples of the plasma processing process include a film formation process, an etching process, and an ashing process.

[0077] When the plasma processing process is completed, the processed substrate WP is unloaded from the processing chamber 12 by a robot arm (not shown) (step S106).

[0078] 12 , the control device 11 may control the RF power supply 16 to supply electromagnetic waves including multiple frequency components belonging to a predetermined frequency bandwidth (broadband electromagnetic waves) from the antenna 30 to the spaces S1 and S2 in the processing vessel 12. In this case, the control device 11 may perform the following process in step S104. That is, the control device 11 may control the RF power supply 16 to adjust the frequencies of the multiple frequency components included in the broadband electromagnetic waves supplied from the antenna 30 to the spaces S1 and S2 in the processing vessel 12 to a target frequency band.

[0079] [Simulation Results at Plasma Ignition] Next, simulation results at plasma ignition will be described with reference to Figs. 13 and 14. Figs. 13 and 14 are diagrams showing an example of simulation results at plasma ignition according to the first embodiment. In Figs. 13 and 14, the simulation conditions are Ar gas as the process gas, a pressure of 50 mTorr (6.67 Pa), and a frequency and power of the source RF signal of 13.56 MHz and 350 W. In Figs. 13 and 14, in order to examine the relative permeability of the resonator array structure 100, a separation distance δ at which a doughnut-shaped plasma can be generated in the space S1 is calculated. Ｓ１ It states that:

[0080] The simulation result 200 shown in FIG. 13 is the Ar 0.01 second after the start of supplying the source RF signal to the antenna 30, that is, after plasma ignition. ＊ Molar concentration [mol / m ３ In the simulation result 200, Ar is distributed in a doughnut shape in the space S1 between the dielectric window 20 and the resonator array structure 100. ＊ In other words, plasma is generated in the area where the molar concentration of Ar is high. ＊ is distributed in the space S2 through the through holes 118 of the resonator array structure 100 and reaches the substrate WP placed on the stage 14. The simulation result 200 shows the right half of the cross section of the processing vessel 12.

[0081] The simulation result 201 shown in FIG. 14 is the Ar concentration on the surface of the substrate WP from 0.001 seconds to 0.01 seconds after the start of supplying the source RF signal to the antenna 30, that is, after plasma ignition. ＊ Molar flux [mol / m ２ In the simulation result 201, the vertical axis indicates the time elapsed from plasma ignition, and the relative permeability (μ / μ ０ ) is shown on the horizontal axis. As shown in the region 202 of the simulation result 201, when the relative permeability is −0.6, Ar ＊ In other words, it can be seen from the simulation result 201 that high density radicals can be obtained by setting the relative permeability of the resonator array structure 100 to -0.6.

[0082] [Separation distance δ Ｓ１ Another Simulation Result] Next, using FIGS. 15 and 16, the separation distance δ Ｓ１ Another simulation result will be described. Figures 15 and 16 are diagrams showing an example of a simulation result of plasma generation according to the first embodiment. In Figures 15 and 16, the simulation conditions are as follows: the relative permeability of the resonator array 100 is set to -0.6, the process gas is Ar gas with a pressure of 50 mTorr, and the frequency and power of the source RF signal are 13.56 MHz and 350 W, respectively. Also, Figures 15 and 16 show the right half of the cross section of the process vessel 12 as a simulation result.

[0083] The simulation result 210 in FIG. 15 shows the separation distance δ Ｓ１ The simulation result 211 in FIG. 16 is obtained when the separation distance δ is set to 0. The distance 212 is, for example, 35 mm. Ｓ１ The simulation results are obtained when the separation distance δ is set to δ . The distance 213 is, for example, 15 mm. Ｓ２ is set to 50 mm or more.

[0084] In the simulation results 210 and 211, Ar is formed in a disk shape in the space S2 between the resonator array 100 and the substrate WP.＊ In other words, plasma is generated in the area where the molar concentration of Ar is high. ＊ ) also reaches the substrate WP. Meanwhile, in the space S1 between the dielectric window 20 and the resonator array structure 100, a low-density plasma is generated.

[0085] 17 is a diagram showing an example of detailed simulation results at the time of plasma ignition according to the first embodiment. Simulation results 220 to 225 shown in FIG. 17 are 1×10 －５ seconds ~ 5×10 －４ 15. In the simulation results 220 to 225, the separation distance δ Ｓ１ The distance 212 (35 mm) is set to the distance 212. The other simulation conditions are also the same as those of the simulation result 210 in FIG.

[0086] The simulation result 220 is 1×10 after plasma ignition. －５ 10 shows the states of spaces S1 and S2 at 1000 s, and plasma is generated (ignited) in space S1, which is directly below dielectric window 20 near antenna 30. Part of the plasma also propagates into space S2 through through-hole 118.

[0087] The simulation result 221 is 1×10 after plasma ignition. －４ 2 shows the states of spaces S1 and S2 at 2000 s, and the plasma density in space S1 is higher than in simulation result 220. Also, part of the plasma is propagating through through-hole 118 into space S2.

[0088] The simulation result 222 shows the 2×10 －４ 2 shows the states of spaces S1 and S2 at 200 s, where the region of high plasma density in space S1 moves toward the central region of space S1. Also, in space S2, the plasma density in the central region corresponding to the lower part of the central region of space S1 is higher than in simulation result 221.

[0089] The simulation result 223 shows the 3×10 －４ 2 shows the states of spaces S1 and S2 at 2 seconds, and the region with high plasma density has shifted from the central region of space S1 to the central region of space S2. In the central region of space S1, plasma of approximately the same density as that in the central region of space S2 in the simulation result 222 remains.

[0090] The simulation result 224 is 4×10 －４ 10 shows the states of the spaces S1 and S2 at 1000 s, and the region with high plasma density has shifted to approximately the central region of the space S2.

[0091] Simulation result 225 shows the 5×10 －４ 15 to 17 show the states of spaces S1 and S2 at 1000 s, and plasma is stably generated in space S2. The plasma density is low in space S1. As shown in the simulation results 210, 211, and 220 to 225 of FIGS. 15 to 17, the separation distance δ Ｓ１ If the distance between the through-holes 118 and the space S1 is less than 50 mm, the plasma ignited in the space S1 propagates to the space S2 through the through-holes 118. In the space S2, the resonator array 100 can generate stable plasma.

[0092] Second Embodiment In the first embodiment, the separation distance δ of the space S1 is Ｓ１ was less than 50 mm, but the separation distance δ Ｓ１ However, it may be set to 50 mm or more. An embodiment in this case will be described as a second embodiment. In the second embodiment, for example, the separation distance δ Ｓ１ , δ Ｓ２ , mutual inductances M1, M2, M3, spaces S1, S2, impedance Z ｐ , Z ｐｍ , Plasma P Ｓ１ , P ｍ , P, etc., which correspond to those in the first embodiment, are explained using the same reference numerals.

[0093] [Configuration of Plasma Processing Apparatus] Figure 18 is a schematic cross-sectional view showing an example of the configuration of a plasma processing apparatus 501 according to the second embodiment of the present disclosure. The plasma processing apparatus 501 includes an apparatus main body 510 and a control device 511. The apparatus main body 510 includes a processing vessel 512, a stage 514, an RF (Radio Frequency) power supply (an example of an electromagnetic wave generator) 516, a dielectric window 520, an antenna 530, a gas supply unit 538, and a resonator array structure 600. The apparatus main body 510 also includes a central gas inlet unit 513. The central gas inlet unit 513 is disposed above the stage 514 and attached to a central opening of the dielectric window 520. The antenna 530 is disposed above or above (externally) the processing vessel 512 (dielectric window 520).

[0094] The processing vessel 512 is formed in a generally cylindrical shape using, for example, anodized aluminum or the like, and provides generally cylindrical spaces S1 and S2 therein. Note that space S1 is an example of a reaction chamber, and space S2 is an example of a processing chamber. The processing vessel 512 is safety grounded. The processing vessel 512 also has a sidewall 512a and a bottom 512b. The central axis of the sidewall 512a is defined as axis Z. The bottom 512b is located at the lower end of the sidewall 512a. An exhaust port 512h for exhaust is provided in the bottom 512b. The upper end of the sidewall 512a is open. The inner wall surface of the sidewall 512a faces the spaces S1 and S2. That is, the sidewall 512a is located such that its inner wall surface faces the spaces S1 and S2.

[0095] An opening 512c for carrying in / out the substrate WP is formed in the side wall 512a. The opening 512c is opened and closed by a gate valve G.

[0096] A dielectric window 520 is provided at the upper end of the side wall 512a, and closes the opening at the upper end of the side wall 512a from above. A lower surface 520a of the dielectric window 520 faces the space S1. That is, the dielectric window 520 is provided with its lower surface 520a facing the space S1.

[0097] The stage 514 is accommodated in the processing vessel 512. The stage 514 is disposed so as to face the resonator array structure 600, which also serves as a shower head, in the direction of the axis Z. The space between the stage 514 and the resonator array structure 600 is space S2. A substrate WP is placed on the stage 514.

[0098] The stage 514 includes a base 514 a and an electrostatic chuck 514 c. The base 514 a is formed in a substantially disk shape from a conductive material such as aluminum. The base 514 a is disposed in the processing chamber 512 so that the central axis of the base 514 a substantially coincides with the axis Z.

[0099] The base 514a is supported by a cylindrical support 548 made of an insulating material and extending in the Z-axis direction. A conductive cylindrical support 550 is provided on the outer periphery of the cylindrical support 548. The cylindrical support 550 extends from the bottom 512b of the processing vessel 512 toward the dielectric window 520 along the outer periphery of the cylindrical support 548. An annular exhaust path 551 is formed between the cylindrical support 550 and the sidewall 512a. The stage 514 may be configured to be movable in the vertical direction (Z-axis direction) by a drive mechanism (not shown), thereby changing the distance between the lower surface of the resonator array structure 600 and the upper surface of the electrostatic chuck 514c. This enables adjustment of the energy level by residence time.

[0100] An annular baffle plate 552 having a plurality of through holes formed in the thickness direction is provided above the exhaust path 551. The above-mentioned exhaust port 512h is provided below the baffle plate 552. An exhaust device 556 having a vacuum pump such as a turbomolecular pump and an automatic pressure control valve is connected to the exhaust port 512h via an exhaust pipe 554. The exhaust device 556 can reduce the pressure in the spaces S1 and S2 to a desired degree of vacuum.

[0101] The base 514a functions as a radio-frequency electrode. A radio-frequency power supply 558 for RF bias is electrically connected to the base 514a via a power feed rod 562 and a matching unit 560. The radio-frequency power supply 558 supplies, via the matching unit 560 and the power feed rod 562, to the base 514a, bias power of a predetermined frequency (e.g., 13.56 MHz) suitable for controlling the energy of ions attracted to the substrate WP.

[0102] The matching unit 560 contains a matcher for matching the impedance on the high frequency power supply 558 side with the impedance on the load side, mainly consisting of the electrodes, plasma, and processing chamber 512. The matcher includes a blocking capacitor for generating a self-bias. If an RF bias is not used, the high frequency power supply 558, matching unit 560, and power feed rod 562 may be omitted.

[0103] An electrostatic chuck 514c is provided on the upper surface of the base 514a. The electrostatic chuck 514c attracts and holds the substrate WP by electrostatic force. The electrostatic chuck 514c has a substantially disc-shaped outer shape and includes an electrode 514d, an insulating film (dielectric film) 514e, and an insulating film (dielectric film) 514f. The electrostatic chuck 514c is disposed on the upper surface of the base 514a so that the central axis of the electrostatic chuck 514c substantially coincides with the axis Z. The electrode 514d of the electrostatic chuck 514c is made of a conductive film and is provided between the insulating films 514e and 514f. A DC power supply 564 is electrically connected to the electrode 514d via a coated wire 568 and a switch 566. The electrostatic chuck 514c can attract and hold the substrate WP on its upper surface by electrostatic force generated by a DC voltage applied from the DC power supply 564. The upper surface of the electrostatic chuck 514c is a mounting surface on which the substrate WP is placed, and faces the space S2. That is, the electrostatic chuck 514c is provided with its upper surface, which is the mounting surface, facing the space S2. An edge ring 514b is also provided on the base 514a. The edge ring 514b is arranged to surround the substrate WP and the electrostatic chuck 514c. The edge ring 514b is also called a focus ring.

[0104] A flow path 514g is provided inside the base 514a. A coolant is supplied to the flow path 514g from a chiller unit (not shown) via a pipe 570. The coolant supplied to the flow path 514g is returned to the chiller unit via a pipe 572. The coolant, the temperature of which is controlled by the chiller unit, circulates through the flow path 514g of the base 514a, thereby controlling the temperature of the base 514a. By controlling the temperature of the base 514a, the temperature of the substrate WP on the electrostatic chuck 514c is controlled via the electrostatic chuck 514c on the base 514a.

[0105] The stage 514 is also provided with a pipe 574 for supplying a heat transfer gas such as He gas between the upper surface of the electrostatic chuck 514c and the rear surface of the substrate WP.

[0106] The RF power supply 516 is coupled to the antenna 530 and configured to generate a source RF signal (source RF power) for plasma generation via at least one impedance matching circuit. In one embodiment, the source RF signal has a frequency within a range of 3 MHz to 3000 MHz. In one embodiment, the RF power supply 516 may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to the antenna 530. As described above, the RF power supply 516 is an example of an electromagnetic wave generator and an example of a high-frequency power supply. The antenna 530 is also an example of an electromagnetic wave supply unit.

[0107] The antenna 530 includes one or more coils. In one embodiment, the antenna 530 may include an outer coil and an inner coil arranged coaxially. In this case, the RF power supply 516 may be connected to both the outer coil and the inner coil, or to either the outer coil or the inner coil. In the former case, the same RF generator within the RF power supply 516 may be connected to both the outer coil and the inner coil, or separate RF generators may be connected to the outer coil and the inner coil separately. In one embodiment, the antenna 530 is a planar coil formed in a substantially circular spiral shape (planar spiral shape). That is, the antenna 530 is wound in a loop shape. Note that the magnetic field generated by the antenna 530 is oriented along the axis Z. The opening of the antenna 530 may have any shape, such as a circle, an ellipse, or a polygon (e.g., a square, a triangle, etc.). Note that the RF power supply 516 and the antenna 530 are an example of a power transmission unit that includes a drive circuit including a coil and is configured to generate and radiate electromagnetic waves from the coil. Furthermore, the antenna 530 supplies a magnetic field component perpendicular to the plane on which a plurality of resonators 601 (described later) are arranged.

[0108] Furthermore, when the antenna 530 includes an outer coil and an inner coil, the outer coil functions as a primary coil connected to the RF power supply 516. In one embodiment, the outer coil is a planar coil formed in a substantially circular spiral shape. The inner coil functions as a secondary coil inductively coupled to the primary coil. In other words, the inner coil is not connected to the RF power supply 516. In one embodiment, the inner coil is a planar coil formed in a substantially circular ring shape. In one embodiment, the inner coil is connected to a variable capacitor, and the direction and magnitude of the current flowing through the inner coil are controlled by controlling the capacitance of the variable capacitor. The outer coil and the inner coil may be disposed at the same height or at different heights. In one embodiment, the inner coil is disposed at a lower position than the outer coil.

[0109] The gas inlet is configured to introduce at least one process gas from the gas supply unit 538 into the space S1. In one embodiment, the gas inlet includes a center gas injector (CGI) 513. The center gas injector 513 is disposed above the stage 514 and the resonator array 600 and attached to a central opening formed in the dielectric window 520. The center gas injector 513 has at least one gas supply port 513a, at least one gas flow path 513b, and at least one gas inlet port 513c. The process gas supplied to the gas supply port 513a passes through the gas flow path 513b and is introduced into the space S1 from the gas inlet port 513c. The process gas is excited by electromagnetic waves supplied from the antenna 530 to the space S1 via the dielectric window 520 and the resonator array 600. As a result, the process gas in the space S1 is converted into plasma, and radicals and unactivated process gas contained in the plasma are supplied to the space S2 through through-holes 618 and 633, which will be described later. Furthermore, ions contained in the plasma recombine to form radicals as they pass through the through-holes 618, 633, and these radicals are similarly supplied to the space S2. The space S2 becomes a high-density radical region, and the substrate WP is processed by the radicals. Note that the gas introduction part may include, in addition to or instead of the central gas injection part 513, one or more side gas injection parts (SGIs) attached to one or more openings formed in the side wall 512a.

[0110] The gas supply 538 may include at least one gas source 538a and at least one flow controller 538b. In one embodiment, the gas supply 538 is configured to supply at least one process gas from a corresponding gas source 538a to the gas inlet through a corresponding flow controller 538b. Each flow controller 538b may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 538 may include one or more flow modulation devices to modulate or pulse the flow rate of the at least one process gas.

[0111] The resonator array 600 is formed by arranging a plurality of resonators that can resonate with the magnetic field component of the electromagnetic wave and that are smaller in size than the wavelength of the electromagnetic wave, and is located, for example, above the opening 512c in the processing vessel 512 while being supported by a support member 522. The resonator array 600 also includes a through-hole 618 (described later) that separates the space S1 from the space S2 and communicates the space S1 with the space S2. In other words, the resonator array 600 is an example of a showerhead that includes the through-hole 618. The support member 522 may also have a sealing structure that seals the space S1 from the space S2.

[0112] Here, the separation distance between the space S1 and the space S2 is defined as follows: Ｓ１ is the distance between the lower surface 520a of the dielectric window 520 and the upper surface of the resonator array 600 (the surface opposite to the lower surface 520a). Ｓ２ is the distance between the bottom surface of the resonator array 600 (the surface facing the top surface of the substrate WP) and the top surface of the substrate WP. The top surface of the resonator array 600 is also referred to as the first surface of the resonator array 600, and the bottom surface of the resonator array 600 is also referred to as the second surface of the resonator array 600. Furthermore, the distance between the top and bottom surfaces of the resonator array 600, i.e., the thickness of the resonator array 600, is referred to as thickness δ ｔ Let's say.

[0113] In the plasma processing apparatus 501 of the second embodiment, the separation distance δ between the dielectric window 520 and the resonator array structure 600 is Ｓ１ This is an example where the separation distance δ is equal to or greater than a specific value. Ｓ１ That is, in the second embodiment, the specific value of is 50 mm. Ｓ１) is 50 mm or more. In this case, the space S1 between the dielectric window 520 and the resonator array 600 has a strong coupling with the antenna 530, and plasma is generated along with the first surface side of the resonator array 600 that resonates with the electromagnetic wave. Note that the bulk of the resonator array 600 that resonates with the electromagnetic wave has a negative magnetic permeability. In other words, the resonator array 600 is formed so that the overall magnetic permeability is negative. Furthermore, the separation distance δ of the space S2 Ｓ２ is a distance greater than or equal to a specific value. Ｓ２ The specific value of is not particularly limited, and is, for example, 10 mm. Ｓ１ By setting the distance to a specific value or more, the stability of the plasma generated in the space S1 can be improved.

[0114] That is, by positioning the resonator array 600 within the processing vessel 512, the electromagnetic waves supplied to the space S1 by the antenna 530 can resonate with the multiple resonators of the resonator array 600. Resonance between the electromagnetic waves and the multiple resonators allows the electromagnetic waves to be efficiently supplied to the space S1 of the processing vessel 512 and the magnetic permeability of the space S1 to be negative. When the magnetic permeability of the space S1 is negative, even if the electron density of the plasma generated in the space S1 reaches the cutoff density and the dielectric constant of the space S1 is negative, the refractive index becomes a real number according to the above formula (1), allowing the electromagnetic waves to propagate in the space S1. As a result, even if the electron density of the plasma generated in the space S1 reaches the cutoff density, the electromagnetic waves can propagate beyond the plasma's skin depth, and the power of the electromagnetic waves is efficiently absorbed by the plasma. As a result, high-density plasma can be generated over a wide area beyond the plasma's skin depth. That is, the plasma processing apparatus 501 according to the second embodiment can stabilize plasma in the space S1 and achieve high density over a wide area.

[0115] Here, the detailed configuration of the resonator array 600 will be described with reference to Fig. 18 and Fig. 19. Fig. 19 is a plan view showing an example of the configuration of the support member 522 and the resonator array 600 according to the second embodiment, as viewed from above. In Fig. 19, the support member 522 and the resonator array 600 are shown in a disk shape.

[0116] The resonator array structure 600 is formed, for example, by arranging a plurality of resonators 601 such that their longitudinal directions extend along radial lines from the center of the resonator array structure 600. For example, the resonator array structure 600 has two resonators 601 arranged along each of eight radial lines spaced at 45-degree intervals. The resonators 601 are arranged such that the coils 611 face the center of the resonator array structure 600 and the coils 611 of the outer resonators 601 are adjacent to the capacitors 612 of the inner resonators 601. That is, the inner resonators 601 are arranged at equal intervals on a first circle, and the outer resonators 601 are arranged at equal intervals on a second circle. The resonators 601 are integrally formed as the resonator array structure 600. The resonators 601 may be formed separately and fitted into a radial frame or bonded to each other to form the resonator array 600. The substrate WP facing the resonator array 600 is preferably disposed in a region where the coils 611 of the resonators 601 arranged on the outside in the direction of the axis Z in Fig. 18 are present. In the following description, the resonator array 600 may be referred to as a metamaterial, and each of the resonators 601 may be referred to as a metaatom.

[0117] Fig. 20 is a cross-sectional view showing an example of a cross section of a single resonator in the resonator array structure according to the second embodiment. Fig. 20 shows a cross section of a single resonator 601 in the array direction (the direction of radial lines from the center of the resonator array structure 600), using a resonator 601 as an example among the multiple resonators 601 shown in Fig. 19 . The single resonator 601 has a series resonant circuit consisting of a coil 611 and a capacitor 612, surrounded by a dielectric 615. The magnetic field generated by the antenna 530 is directed to pass through the coil 611.

[0118] In the resonator 601, a dielectric 615a, which is a plate-shaped region inside the dielectric 615, is sandwiched between electrodes 616 and 617 of the capacitor 612. A coil 611 is formed on the upper surface of the dielectric 615a, on which the electrode 616 is formed. The coil 611 is, for example, a circular flat spiral coil with three turns, and one end is connected to the electrode 616 via a lead portion 613. The other end of the coil 611 penetrates the dielectric 615a via a through hole 614, appears on the lower surface of the dielectric 615a, on which the electrode 617 is formed, and is connected to the electrode 617 via the lead portion 613. That is, from the perspective of lamination, the resonator 601 has the coil 611 formed by laminating one layer of a circular flat spiral coil, and the capacitor 612 formed by laminating two layers of electrodes (metal) and one layer of dielectric. As a result, the resonator 601 can form a series resonant circuit with the coil 611, which is a circular flat spiral coil with three turns, and the capacitor 612, which has two layers of electrodes. That is, the resonator 601 is an example of a resonator in which the series resonant circuit is a lumped constant circuit.

[0119] Furthermore, a through-hole 618 is provided at the center of the coil 611. The through-hole 618 connects the upper space S1 of the resonator array 600 with the lower space S2. That is, the resonator array 600 has the through-hole 618 penetrating from the upper surface to the lower surface. In other words, the resonator array 600 includes the through-hole 618 penetrating from the first surface to the second surface opposite the first surface. The through-hole 618 has, for example, a circular cross section. The through-hole 618 has, for example, a diameter of 10 mm or less, thereby recombining ions and allowing radicals and unactivated process gas to pass from the space S1 to the space S2. It is more preferable that the through-hole 618 has a diameter of, for example, 2 mm or less. That is, the through-hole 618 has a diameter that does not allow ions to pass from the space S1 to the space S2. That is, the radicals and unactivated process gas contained in the plasma generated in the space S1 are supplied to the space S2 through the through-hole 618. Furthermore, ions contained in the plasma recombine to become radicals when passing through the through-holes 618, and these radicals are similarly supplied to the space S2. The space S2 becomes a high-density radical region, and the substrate WP is processed by the radicals.

[0120] The resonator array structure 600 is composed of an array structure of a plurality of resonators 601, and each of the plurality of resonators 601 has a relatively small area compared to the antenna 530 and the substrate WP. Therefore, the resonator array structure 600 can reduce loss compared to loss caused by electrostatic induction in the internal antenna of the ICP.

[0121] Furthermore, the resonator array 600 may use resonators of distributed constant circuits as the resonators 601. Fig. 21 is a plan view showing another example of the configuration of the support member and the resonator array according to the second embodiment as viewed from above.

[0122] The resonator array 600a shown in FIG. 21 is formed by arranging a plurality of resonators 621, each of which can resonate with the magnetic field component of an electromagnetic wave and has a size smaller than the wavelength of the electromagnetic wave, in a lattice pattern. Specifically, as shown in FIG. 21 , the plurality of resonators 621 are arranged in a plane parallel to the lower surface 520a of the dielectric window 520 in the planar resonator array 600a. That is, when viewed from the lower surface 520a, the C-shaped ring members 631, which are shown transparently, are arranged in a lattice pattern so that the C shape is visible. The resonator array 600a includes, for example, eight rows and eight columns of resonators 621. Although the boundaries between the resonators 621 are shown as boundaries 625, in reality, the resonators 621 are integrally formed as the resonator array 600a. The resonators 621 may be formed separately and then fitted into a lattice frame or bonded to each other to form the resonator array 600a. Each of the multiple resonators 621 forms a series resonant circuit consisting of a capacitor equivalent element and a coil equivalent element. The series resonant circuit is realized by patterning a conductor on a plane. The magnetic field generated by the antenna 530 is directed to pass through the C-shaped ring member 631.

[0123] FIG. 22 is a cross-sectional view showing another example of a cross section of a single resonator in the resonator array according to the second embodiment. In FIG. 22 , a cross section of a single resonator 621 is shown, using one resonator 621 as an example among a plurality of resonators 621 formed integrally. As shown in FIGS. 21 and 22 , the single resonator 621 is located within a region surrounded by a boundary 625. That is, in the example shown in FIGS. 21 and 22 , the resonator 621 has two C-shaped ring members 631 each surrounded by a dielectric 632. The dielectric 632 may be formed such that the thickness from the first C-shaped ring member 631 to the first surface 622 is thinner than the thickness from the second C-shaped ring member 631 to the second surface 623 on the side where plasma is generated.

[0124] The through-hole 633 communicates between the space S1 and the space S2. The through-hole 633 has, for example, a circular cross section. The through-hole 633 functions as an ion trap, similar to the through-hole 618 of the resonator 601 in the resonator array structure 600, and supplies radicals and unactivated processing gas contained in the plasma generated in the space S1 to the space S2.

[0125] Referring again to Fig. 18, the control device 511 has a processor, a memory, and an input / output interface. The memory stores programs, process recipes, and the like. The processor reads and executes the programs from the memory, thereby controlling each part of the device main body 510 via the input / output interface based on the process recipes stored in the memory.

[0126] For example, when plasma is generated in the space S1, the control device 511 controls the plurality of resonators 601 so that the electromagnetic waves supplied to the space S1 by the antenna 530 resonate with the plurality of resonators 601 in a target frequency band higher than the resonant frequency fr of the plurality of resonators 601. Here, the resonant frequency fr is, for example, a transmission characteristic value (e.g., S ２１ This is the frequency at which the minimum value of

[0127] When the frequency of the electromagnetic wave supplied to the space S1 by the antenna 530 matches the resonance frequency fr (for example, about 68 MHz) of the plurality of resonators 601, ２１The value of ∫ ...

[0128] Regarding the propagation of electromagnetic waves through a plurality of resonators, the relationship between the resonant frequency and the refractive index, the permittivity, and the magnetic permeability has been reported by D. R. Smith, D. C. Vier, Th. Koschny, and C. M. Soukoulis et al. in "Electromagnetic parameter retrieval from inhomogeneous metamaterials" in "PHYSICAL REVIEW E 71, 036617 (2005)," for example.

[0129] In this way, by resonating the electromagnetic wave with the multiple resonators 601 in a target frequency band higher than the resonant frequency fr of the multiple resonators 601, the electromagnetic wave can propagate beyond the skin depth of the plasma even when the plasma electron density reaches the cutoff density. Therefore, the power of the electromagnetic wave can be efficiently absorbed by the plasma. As a result, high-density plasma can be generated over a wide area beyond the skin depth of the plasma. That is, according to the plasma processing apparatus 501 of the second embodiment, by resonating the electromagnetic wave with the multiple resonators 601 in a target frequency band higher than the resonant frequency fr of the multiple resonators 601, high-density plasma can be realized over a wide area.

[0130] [Circuit Model of Power Transmission System] Next, a circuit model of the power transmission system will be described with reference to FIGS. 23 to 25. FIG. 23 is a diagram showing an example of a circuit model of the power transmission system according to the second embodiment. As shown in FIG. 23, the circuit model of a power transmission system 670 corresponding to the plasma processing apparatus 501 is composed of a power transmitting unit 670a and a power receiving unit 670b. The power transmitting unit 670a has an RF power supply 516, a matching box 516d, and an antenna 530. The power receiving unit 670b has a resonator array 600. The antenna 530 and the resonator array 600 are arranged opposite each other via a dielectric window 520 and a space S1. That is, the power receiving unit 670b is arranged between the power transmitting unit 670a and the power transmitting unit 670a and separated from the dielectric window 520, and is configured to include a resonator array 600 formed by arranging a plurality of resonators 601 that can resonate with the magnetic field component of the electromagnetic wave radiated from the power transmitting unit 670a and that have a size smaller than the wavelength of the electromagnetic wave. The resonator array structure 600 in FIG. 23 is shown schematically as a plurality of resonators 601 each having a coil and a capacitor.

[0131] In the circuit model, the RF power supply 516 includes, for example, an alternating current (AC)-direct current (DC) converter 516a, a DC-DC converter 516b, and an inverter 516c. The AC-DC converter 516a converts AC from a commercial power source or the like into DC and outputs the DC to the DC-DC converter 516b. The DC-DC converter 516b converts the DC input from the DC-DC converter 516b into DC of a voltage required by the inverter 516c and outputs the DC to the inverter 516c. The inverter 516c generates a source RF signal from the input DC and outputs it to the antenna 530 via a matching device 516d. The source RF signal has a frequency within a range of 3 MHz to 3000 MHz. When the resonator array structure 600 is used, the resonators 601 are lumped constant circuit resonators, so the frequency of the source RF signal is 300 MHz or less, for example, 13.56 MHz, 27.12 MHz, 40.68 MHz, 60 MHz, or 68 MHz.

[0132] The matching circuit 516d has, for example, a variable capacitor, and performs matching (impedance matching) between the output of the inverter 516c and the input of the antenna 530. Note that the matching circuit 516d may be an inverted-L type or a Π type matching circuit. Furthermore, when power is supplied to the resonator array structure 600 by magnetic field resonance coupling, the matching circuit 516d may function as a resonant capacitor that configures an LC resonant circuit together with the antenna 530. Furthermore, when power is supplied to the resonator array structure 600 by electromagnetic phase-modulating coupling (magnetic field phase-modulating coupling), the matching circuit 516d may function as a matching circuit that performs matching, rather than as a resonant capacitor.

[0133] The antenna 530 and the resonator array structure 600 are coupled by a magnetic field H generated by the antenna 530. The magnetic field H generated by the antenna 530 is supplied to penetrate the coils 611 of the multiple resonators 601 of the resonator array structure 600 via the dielectric window 520 and the space S1. The multiple resonators 601 of the resonator array structure 600 resonate due to the magnetic field H, thereby exciting plasma in the space S1 and / or the space S2.

[0134] Here, the power transmission system of the second embodiment will be compared with a general wireless power supply system. Fig. 24 is a diagram showing an example of a comparison of power transmission systems. Fig. 24 shows a schematic comparison between a general wireless power supply system 650 and a power transmission system 670 of the second embodiment. In both the wireless power supply system 650 and the power transmission system 670, a power transmitting side 671 and a power receiving side 672 are coupled by a magnetic field via space.

[0135] In the wireless power supply system 650, a DC power supply 651, a DC-DC converter 652, an inverter 653, a matching box 654, and a power transmission coil 655 are provided on a power transmission side 671. In addition, in the wireless power supply system 650, a power reception coil 656, a rectifier 657, a smoothing capacitor 658, a DC-DC converter 659, and a load 660 are provided on a power reception side 672. The start and end of power supply are controlled by wireless communication between the DC-DC converter 652 and the inverter 653 on the power transmission side 671 and the DC-DC converter 659 on the power reception side 672 by a control unit (not shown). There is a mutual inductance M ｇ１ are joined together.

[0136] The power transmission system 670 is provided with an AC-DC converter 516a, a DC-DC converter 516b, an inverter 516c, a matching device 516d, and an antenna 530 on a power transmission side 671. The power transmission system 670 is also provided with a resonator array structure 600 on a power receiving side 672. There is a mutual inductance M ｇ２ Furthermore, there is a mutual inductance M between the resonator array structure 600 and the plasma P excited in the space S1 and / or the space S2. ｇ３ As will be described later, the antenna 530 and the space S1 (including when the plasma P is excited) are also coupled by mutual inductance. That is, the power transmitting unit 670a is disposed on the atmospheric space side, which is outside the processing vessel 512 that provides the processing space. The dielectric plate (dielectric window 520) is the top plate of the processing vessel 512. The power receiving unit 670b is disposed inside the processing space so as to be spaced apart from the top plate.

[0137] When comparing the wireless power supply system 650 and the power transmission system 670, on the power transmission side 671, the DC power supply 651 to the power transmission coil 655 correspond to the AC-DC converter 516a to the antenna 530, respectively. On the power receiving side 672, in the wireless power supply system 650, the power received by the power receiving coil 656 is converted to DC and supplied to the load 660, whereas in the power transmission system 670, the power received by the resonator array structure 600 is supplied to the plasma P without being converted to DC. In other words, the power transmission system 670 uses magnetic field coupling (M ｇ３ ) supplies a source RF signal to a load, the plasma P.

[0138] 25 is a diagram showing an example of a case where a circuit model of a plurality of resonators is approximated as a circuit model of a resonator array structure. In FIG. 25, a more detailed circuit model from the antenna 530 to the plasma P of the power transmission system 670 in FIG. 24 is shown. Note that the mutual inductance M ｇ２ In FIG. 25, the mutual inductance M ａ , M ａ１ ~M ａｎ In addition, the mutual inductance M ｇ３ In FIG. 25, the mutual inductance M ｂ , M ｂ１ ~M ｂｎ 25, the resonator array structure 600 is represented as a circuit model of a plurality of resonators 601-1, ..., resonator 601-n, and the corresponding plurality of plasmas are represented as circuit models of plasmas P-1, ..., plasmas P-n. For example, the resonator 601-1 has a mutual inductance M ａ１ and the mutual inductance M ｂ１ The impedance of the plasma is the impedance Z ｐ１ , ..., impedance Z ｐｎ The details of the circuit model of the plurality of resonators 601 and the corresponding plurality of plasmas are the same as those of the circuit model 681, and therefore will not be described here.

[0139] In the circuit model 680, the multiple resonators 601-1, ..., 601-n have the same characteristics, and therefore can be approximated by a circuit model 681 using one resonator array structure 600. The resonator array structure 600 of the circuit model 681 has an inductance L ｍ１ , L ｍ２ , wiring resistance R ｍ and capacitance C ｍ are connected in series to form a series resonant circuit. ｍ is the geometric inductance L determined by the shape of the plasma current ｇｍ , and the plasma impedance Z ｐｍ are connected in series. Furthermore, the antenna 530 and the inductance L ｍ１ The mutual inductance between ａ and the inductance L ｍ２ and the geometric inductance L ｇｍ The mutual inductance between ｂ When a current flows through the antenna 530, the mutual inductance M ａ A current I flows through the resonator array structure 600 coupled by ｍ flows through the resonator array structure 600 and the mutual inductance M ｂ The plasma P is bound by ｍ In the equivalent circuit of ｐｍ Here, controlling the magnetic permeability μ and permittivity ε of the plasma by the LC resonance of the resonator array structure 600 allows the plasma P ｍ Impedance Z ｐｍ In other words, it is found that it is difficult to control the magnetic permeability μ and the dielectric constant ε of the plasma in a conventional ICP that does not use the resonator array structure 600.

[0140] [Circuit Model of Space S1 and Resonator Array 600] Next, a circuit model of the space S1 and the resonator array 600 will be described with reference to Fig. 26 to Fig. 28. Fig. 26 is a diagram showing an example of a circuit model of the space S1 and the resonator array. The circuit model 682 shown in Fig. 26 is a circuit model including the RF power supply 516, the matching box 516d, the antenna 530, and the space S1 and the resonator array 600 in the internal space of the processing vessel 512.

[0141] In the circuit model 682, an RF power supply 516, a matching device 516d, and an antenna 530 are connected in series as a power transmission circuit. The RF power supply 516 includes an AC-DC converter 516a, a DC-DC converter 516b, and an inverter 516c. The antenna 530 has an inductance L ａ and resistor R ａ In the circuit model 682, the plasma P Ｓ１ (The doughnut-shaped plasma P described later Ｓ１ ) is generated, and the inductance L ｐ and impedance Z ｐ The inductance L of the space S1 is ｐ is the inductance L of the antenna 530 ａ In the circuit model 682, similarly to the circuit model 681, the inductance L ｍ１ is the inductance L of the antenna 530 ａ In the circuit model 682, similarly to the circuit model 681, the inductance L ｍ２ is Plasma P ｍ (Plasma P using metamaterials, which will be described later) ｍ ) geometric inductance L ｇｍ The mutual inductance M2 is the mutual inductance M ａ The mutual inductance M3 corresponds to the mutual inductance M ｂ Corresponds to.

[0142] In other words, the antenna 530 (coil) and the space S1 (first space) between the dielectric window 520 (dielectric plate) in which the antenna 530 is arranged and the upper surface (first surface) of the resonator array structure 600 are coupled by a first coupling (mutual inductance M1) due to a magnetic field, and a first load (impedance Z ｐ ) is connected. The antenna 530 and the resonator array structure 600 are coupled by a second coupling (mutual inductance M2) due to the transmission of a magnetic field through the space S1 (first space). The resonator array structure 600 and the space S2 (second space) in contact with the second surface opposite to the first surface of the resonator array structure 600 are coupled by a third coupling (mutual inductance M3) due to the magnetic field, and a second load (impedance Z ｐｍ ) are connected. The first coupling and the second coupling are coupled in parallel. Furthermore, the first load and the second load are plasma.

[0143] 27 is a diagram showing an example of a circuit model at the time of plasma generation according to the second embodiment. FIG. 28 is a diagram showing an example of a plasma generation position according to the second embodiment. The circuit model 683 shown in FIG. 27 is Ｓ１ 5. This is a circuit model in which the coupling between the space S1 and the antenna 530 is strong when the mutual inductance M1 is long (for example, 50 mm or more). In other words, the circuit model 683 is a case in which the mutual inductance M1 is larger than the mutual inductance M2. In other words, the first coupling (mutual inductance M1) is stronger than the second coupling (mutual inductance M2).

[0144] As shown in circuit model 683 and plasma generation example 684 in Fig. 28, antenna 530 corresponds to the external coil of an ICP coil in terms of positional relationship, and transmits electromagnetic waves to resonator array structure 600. Resonator array structure 600 corresponds to the internal coil of an internal antenna type ICP coil. Since a source RF signal is supplied to antenna 530 from RF power supply 516 via matching box 516d, antenna 530 and space S1 directly below dielectric window 520 resonate, and a resonant current I flows through antenna 530. ＲＦ is playing.

[0145] When plasma is generated, a sheath is generated in the dielectric window 520 and the resonator array structure 600. The space S1 between the dielectric window 520 and the resonator array structure 600 is separated by a distance δ Ｓ１ is sufficiently large compared to the thickness of the sheath, so that a donut-shaped plasma P Ｓ１ is generated. A doughnut-shaped plasma P Ｓ１ The electromagnetic waves that did not contribute to the generation of the resonators 601 propagate within the processing vessel 512, and when the resonant frequencies of the resonators 601 of the resonator array 600 match the frequency of the source RF signal, the resonators 601 of the resonator array 600 resonate. At this time, the control device 511 controls the power and power supply frequency of the RF power supply 516 (drive circuit) so that the second coupling (mutual inductance M2) becomes magnetic field resonance coupling. When the resonators 601 of the resonator array 600 resonate, plasma P ｍ As shown in FIG. 28, in the space S1, a doughnut-shaped plasma P Ｓ１ and metamaterial plasma P ｍ In other words, in the space S1, a donut-shaped plasma P, which is an ICP, is generated. Ｓ１ Plasma P by metamaterial ｍ With the assistance of the resonator array 600, a metamaterial plasma (plasma P) that is a high-density plasma is generated. The metamaterial plasma is a plasma that includes the plasma (plasma metamaterial state) generated in the resonator array 600. That is, as shown in the plasma generation example 684, the plasma can be confined in the space S1. That is, damage to the substrate WP can be suppressed. The resonator array 600 also functions as a metamaterial screen that converges the magnetic field H.

[0146] Radicals contained in the metamaterial plasma (plasma P) and unactivated processing gas are supplied to the space S2 through the through-holes 618 of the resonator array 600. Furthermore, ions contained in the metamaterial plasma (plasma P) recombine to form radicals as they pass through the through-holes 618, and these radicals are similarly supplied to the space S2. In other words, the through-holes 618 function as an ion trap. The space S2 becomes a high-density radical region, and the substrate WP is processed by these radicals. Furthermore, since the resonator array 600 functions as a shower head, the substrate WP can be irradiated with high-density radicals at a closer distance.

[0147] [Plasma Control Process] Next, an example of a plasma control process using the plasma processing apparatus 501 according to the second embodiment will be described. Fig. 29 is a flowchart showing an example of the process flow of the plasma control process according to the second embodiment. The plasma control process shown in Fig. 29 is realized by the control device 511 controlling each part of the apparatus main body 510.

[0148] First, the substrate WP is loaded into the processing vessel 512 and placed on the electrostatic chuck 514c (step S601). Then, the control device 511 opens the valve of the gas source 538a and controls the flow rate controller 538b so that a predetermined flow rate of the processing gas is supplied into the processing vessel 512. Then, the control device 511 controls the exhaust device 556 to adjust the pressure inside the processing vessel 512 (step S602).

[0149] Next, the control device 511 controls the RF power supply 516 to supply electromagnetic waves from the antenna 530 to the space S1 within the processing vessel 512 (step S603). Furthermore, when supplying electromagnetic waves to the space S1, the control device 511 controls the power and power supply frequency of the RF power supply 516 so that the second coupling (mutual inductance M2) becomes magnetic resonance coupling. This generates plasma of the processing gas within the processing vessel 512. At this time, it is assumed that the electron density of the plasma reaches a cutoff density. When the electron density of the plasma reaches the cutoff density, electromagnetic waves cannot propagate within the space S1 within the processing vessel 512.

[0150] Therefore, the control device 511 controls the RF power supply 516 to adjust the frequency of the electromagnetic wave supplied from the antenna 530 to a frequency within a target frequency band (step S604). This generates resonance between the electromagnetic wave and the multiple resonators 601, making both the permittivity and permeability of the plasma in the space S1 negative. As can be seen from the above equation (1), this enables the electromagnetic wave to propagate through the space S1. As a result, the electromagnetic wave can propagate beyond the plasma skin depth in the space S1 within the processing vessel 512, and the electromagnetic wave power is efficiently injected into the plasma. As a result, high-density plasma is generated over a wide area beyond the plasma skin depth. The power supply frequency in step S603 may be set to a frequency within a target frequency band that results in a negative refractive index.

[0151] Then, radicals and unactivated processing gas contained in the plasma generated in the space S1 within the processing vessel 512 are supplied to the space S2 through the through-holes 618 of the resonator array 600. The space S2 becomes a high-density radical region, and the radicals perform a plasma processing process on the substrate WP (step S605). Examples of the plasma processing process include a film formation process, an etching process, and an ashing process.

[0152] When the plasma treatment process is completed, the processed substrate WP is unloaded from the treatment chamber 512 by a robot arm (not shown) (step S606).

[0153] 29 , the control device 511 may control the RF power supply 516 to supply electromagnetic waves including multiple frequency components belonging to a predetermined frequency bandwidth (broadband electromagnetic waves) from the antenna 530 to the space S1 in the processing vessel 512. In this case, the control device 511 may perform the following process in step S604. That is, the control device 511 may control the RF power supply 516 to adjust the frequencies of the multiple frequency components included in the broadband electromagnetic waves supplied from the antenna 530 to the space S1 in the processing vessel 512 to a target frequency band.

[0154] [Simulation Results at Plasma Ignition] Next, the simulation results at plasma ignition will be described with reference to Fig. 30 and Fig. 31. Fig. 30 and Fig. 31 are diagrams showing an example of the simulation results at plasma ignition according to the second embodiment. In Fig. 30 and Fig. 31, the simulation conditions are Ar gas as the process gas, a pressure of 50 mTorr (6.67 Pa), and a frequency and power of the source RF signal of 13.56 MHz and 350 W.

[0155] The simulation result 700 shown in FIG. 30 is the Ar 0.01 second after the start of supplying the source RF signal to the antenna 530, that is, after plasma ignition. ＊ Molar concentration [mol / m ３ In the simulation result 700, Ar is distributed in a doughnut shape in the space S1 between the dielectric window 520 and the resonator array structure 600. ＊ In other words, plasma is generated in the area where the molar concentration of Ar is high. ＊ is distributed in the space S2 through the through-holes 618 of the resonator array structure 600 and reaches the substrate WP placed on the stage 514. The simulation result 700 shows the right half of the cross section of the processing vessel 512.

[0156] The simulation result 701 shown in FIG. 31 is the Ar concentration on the surface of the substrate WP from 0.001 seconds to 0.01 seconds after the start of supplying the source RF signal to the antenna 530, that is, after plasma ignition. ＊ Molar flux [mol / m ２ In the simulation result 701, the vertical axis indicates the time elapsed from plasma ignition, and the relative permeability (μ / μ ０ ) is shown on the horizontal axis. As shown in the region 702 of the simulation result 701, when the relative permeability is −0.6, Ar ＊ In other words, it can be seen from the simulation result 701 that a high density of radicals can be obtained by setting the relative permeability of the resonator array structure 600 to −0.6.

[0157] [Separation distance δ Ｓ１Another Simulation Result] Next, using FIGS. 32 to 36, the separation distance δ Ｓ１ Another simulation result will be described. Figures 32 to 36 are diagrams showing an example of a simulation result of plasma generation according to the second embodiment. In Figures 32 to 36, the simulation conditions are as follows: the relative permeability of the resonator array structure 600 is set to -0.6, the process gas is Ar gas with a pressure of 50 mTorr, and the frequency and power of the source RF signal are 13.56 MHz and 350 W. Also, Figures 32 to 36 show the right half of the cross section of the processing vessel 512 as a simulation result.

[0158] The simulation result 710 in FIG. 32 shows the separation distance δ Ｓ１ The simulation result 710 shows a simulation result when the separation distance δ is set to 135 mm. The distance 715 is, for example, 135 mm. Ｓ２ The simulation result 711 in FIG. 33 shows that the separation distance δ is the shortest in the space S1. Ｓ１ The simulation result 712 in FIG. 34 is obtained when the separation distance δ is set to 115 mm. The distance 716 is, for example, 115 mm. Ｓ１ The simulation result 713 in FIG. 35 is obtained when the separation distance δ is set to 0.5 mm. The distance 717 is, for example, 95 mm. Ｓ１ This is a simulation result when the distance 718 is set to 75 mm.

[0159] In the simulation results 710 to 713, Ar is formed in a disk shape in the space S1 between the dielectric window 520 and the resonator array structure 600. ＊ In other words, plasma is generated in the area where the molar concentration of Ar is high. ＊ It can be seen that the light passes through the through-holes 618 of the resonator array structure 600 and is distributed in the space S2, and also reaches the substrate WP.

[0160] The simulation result 714 in FIG. 36 shows the separation distance δ Ｓ１The simulation result 714 shows a case where the distance 719 is set to 55 mm. The distance 719 is, for example, 55 mm. In the simulation result 714, Ar is distributed in a doughnut shape in the space S1 between the dielectric window 520 and the resonator array structure 600. ＊ In other words, plasma is generated in the area where the molar concentration of Ar is high. ＊ is distributed in the space S2 through the through-holes 618 of the resonator array structure 600 and reaches the substrate WP. Ｓ１ If the distance is 50 mm or more, stable plasma generation by the resonator array structure 600 can be realized in the space S1.

[0161] According to each of the above-described embodiments, a power transmission system (power transmission system 170, 670) includes a power transmitting unit (power transmitting unit 170a, 670a) and a power receiving unit (power receiving unit 170b, 670b). The power transmitting unit includes a drive circuit (RF power supply 16, 516) including a coil (antenna 30, 530) and is configured to generate and radiate electromagnetic waves from the coil. The power receiving unit is arranged between the power transmitting unit and the power transmitting unit via a dielectric plate (dielectric window 20, 520) and is spaced apart from the dielectric plate. The power receiving unit is configured to include a resonator array structure (resonator array structure 100, 100a, 600, 600a) formed by arranging a plurality of resonators (resonators 101, 121, 601, 621) that can resonate with the magnetic field component of the electromagnetic waves radiated from the power transmitting unit and have a size smaller than the wavelength of the electromagnetic waves. The coil and a first space (space S1) between the dielectric plate on which the coil is disposed and the first surface of the resonator array structure are coupled by a first coupling (mutual inductance M1) due to a magnetic field, and a first load (impedance Z ｐ ) is connected. The coil and the resonator array structure are coupled by a second coupling (mutual inductance M2) due to the transmission of a magnetic field through the first space. The resonator array structure and a second space (space S2) in contact with a second surface of the resonator array structure opposite to the first surface are coupled by a third coupling (mutual inductance M3) due to the magnetic field, and a second load (impedance Zｐｍ As a result, stable plasma generation can be achieved by the resonator array structure.

[0162] Furthermore, according to the first embodiment, the second bond is stronger than the first bond, and as a result, a high-density plasma can be generated in the second space.

[0163] Furthermore, according to the second embodiment, the first bond is stronger than the second bond, and as a result, high-density plasma can be generated in the first space.

[0164] Furthermore, according to the first embodiment, the second coupling is magnetic resonance coupling, which makes it possible to efficiently supply (transmit) electromagnetic waves to the high-density plasma generated in the second space.

[0165] According to the second embodiment, the second coupling is magnetic resonance coupling, which allows efficient supply (transmission) of electromagnetic waves to the high-density plasma generated in the first space.

[0166] Furthermore, according to the first embodiment, the first coupling and the second coupling are coupled in parallel, which makes it possible to realize stable plasma generation by the resonator array structure in the second space.

[0167] According to the second embodiment, the first coupling and the second coupling are coupled in parallel, thereby realizing stable plasma generation by the resonator array structure in the first space.

[0168] Furthermore, according to each embodiment, the power transmitting unit is disposed on the atmospheric space side, which is outside the processing vessel (processing vessel 12, 512) that provides the processing space (space S1, S2). The dielectric plate is the top plate of the processing vessel. The power receiving unit is disposed inside the processing space so as to be spaced apart from the top plate. As a result, stable plasma generation by the resonator array structure can be achieved inside the processing vessel.

[0169] According to each embodiment, the first load and the second load are plasma, and as a result, stable plasma generation by the resonator array structure can be realized.

[0170] Furthermore, according to the first embodiment, the distance between the underside of the top plate and the first surface of the resonator array structure is less than 50 mm, which makes it possible to generate high-density plasma in the second space (space S2) while igniting plasma in the first space.

[0171] According to the second embodiment, the distance between the lower surface of the top plate and the first surface of the resonator array is 50 mm or more, so that high-density plasma can be generated in the first space.

[0172] Furthermore, according to the first embodiment, the resonator array structure includes through holes (through holes 118, 133) that penetrate the first surface and the second surface opposite to the first surface, so that high-density plasma can be generated in the second space (space S2) while plasma is ignited in the first space.

[0173] According to the second embodiment, the resonator array structure includes through holes (through holes 618, 633) that penetrate from the first surface to the second surface opposite to the first surface, thereby enabling high-density radicals to be supplied to the second space (space S2).

[0174] Furthermore, according to the first embodiment, the resonator array is formed so as to have negative magnetic permeability as a whole, which makes it possible to generate metamaterial plasma (high-density plasma) in the second space.

[0175] According to the second embodiment, the resonator array is formed to have a negative magnetic permeability as a whole, so that a metamaterial plasma (high-density plasma) can be generated in the first space, which is a combination of the ICP and the plasma generated by the resonator array.

[0176] Furthermore, according to the first embodiment, the relative magnetic permeability is −0.6, which results in a higher density plasma being generated in the second space (space S2).

[0177] Furthermore, according to the second embodiment, the relative magnetic permeability is −0.6, which makes it possible to supply radicals at a higher density to the second space (space S2).

[0178] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and various omissions, substitutions, and modifications may be made in the above embodiments without departing from the scope and spirit of the appended claims.

[0179] In the above-described embodiments, the power transmission systems 170 and 670 are applied to the plasma processing apparatuses 1 and 501, respectively. However, the present invention is not limited to this. For example, power may be supplied to a load coupled to the resonator array structures 100 and 600 by a magnetic field.

[0180] The present disclosure can also be configured as follows. (1) A power transmission system comprising: a power transmitting unit having a drive circuit including a coil and configured to generate and radiate electromagnetic waves from the coil; and a power receiving unit arranged between the power transmitting unit and the power receiving unit and separated from the dielectric plate by a dielectric plate, the power receiving unit including a resonator array structure formed by arranging a plurality of resonators that can resonate with a magnetic field component of the electromagnetic waves radiated from the power transmitting unit and have a size smaller than the wavelength of the electromagnetic waves; wherein the coil and a first space between the dielectric plate on which the coil is arranged and a first surface of the resonator array structure are coupled by a first coupling due to a magnetic field, and a first load is connected in series to the first coupling; the coil and the resonator array structure are coupled by a second coupling due to transmission of a magnetic field through the first space; and the resonator array structure and a second space in contact with a second surface of the resonator array structure opposite the first surface are coupled by a third coupling due to a magnetic field, and a second load is connected in series to the third coupling. (2) The power transmission system according to (1), wherein the second coupling is stronger than the first coupling. (3) The power transmission system according to (1) or (2), wherein the second coupling is magnetic resonance coupling. (4) The power transmission system according to any one of (1) to (3), wherein the first coupling and the second coupling are coupled in parallel. (5) The power transmission system according to any one of (1) to (4), wherein the power transmitting unit is disposed on an atmospheric space side outside a processing chamber providing a processing space, the dielectric plate is a top plate of the processing chamber, and the power receiving unit is disposed inside the processing space so as to be spaced apart from the top plate. (6) The power transmission system according to (5), wherein the first load and the second load are plasma. (7) The power transmission system according to (5) or (6), wherein a distance between a lower surface of the top plate and the first surface of the resonator array structure is less than 50 mm.(8) The power transfer system according to any one of (5) to (7), wherein the resonator array structure includes a through hole penetrating the first surface and a second surface opposite the first surface. (9) The power transfer system according to any one of (1) to (8), wherein the resonator array structure is formed so that the magnetic permeability is negative overall. (10) The power transfer system according to (9), wherein the relative magnetic permeability is −0.6. (11) The power transfer system according to (1), wherein the first coupling is stronger than the second coupling. (12) The power transfer system according to (11), wherein the second coupling is magnetic field resonance coupling. (13) The power transfer system according to (11) or (12), wherein the first coupling and the second coupling are coupled in parallel. (14) The power transmission system according to any one of (11) to (13), wherein the power transmitting unit is disposed on the atmospheric space side outside a processing chamber that provides a processing space, the dielectric plate is a top plate of the processing chamber, and the power receiving unit is disposed inside the processing space so as to be spaced apart from the top plate. (15) The power transmission system according to (14), wherein the first load and the second load are plasma. (16) The power transmission system according to (14) or (15), wherein a distance between a lower surface of the top plate and the first surface of the resonator array is 50 mm or more. (17) The power transmission system according to any one of (14) to (16), wherein the resonator array includes a through hole penetrating the first surface and a second surface opposite the first surface. (18) The power transmission system according to any one of (11) to (17), wherein the resonator array is formed so as to have negative magnetic permeability overall. (19) The power transmission system according to (18), wherein the relative permeability is −0.6.(20) A power transmitting unit including a drive circuit including a coil and configured to generate electromagnetic waves and radiate them from the coil; and a power receiving unit arranged between the power transmitting unit and the power receiving unit with a dielectric plate interposed therebetween and spaced apart from the dielectric plate, the power receiving unit including a resonator array structure formed by arranging a plurality of resonators that can resonate with a magnetic field component of the electromagnetic waves radiated from the power transmitting unit and have a size smaller than the wavelength of the electromagnetic waves, wherein the coil and a first space between the dielectric plate on which the coil is arranged and a first surface of the resonator array structure are coupled by a first coupling due to a magnetic field, and a first load is connected in series with the first coupling, and the coil and the resonator array structure are coupled by a second coupling due to the transmission of a magnetic field through the first space, A power transmission method for a power transmission system, in which the resonator array structure and a second space adjacent to a second surface of the resonator array structure opposite the first surface are coupled by a third coupling due to a magnetic field, and a second load is connected in series with the third coupling, the power transmission method comprising controlling the drive circuit so that the second coupling becomes a magnetic resonance coupling.

[0181] 1,501 Plasma processing apparatus 10,510 Apparatus main body 11,511 Control device 12,512 Processing container 14,514 Stage 16,516 RF power supply 20,520 Dielectric window 30,530 Antenna 38,538 Gas supply unit 100,100a,600,600a Resonator array structure 101,121,601,621 Resonator 118,133,618,633 Through hole 170,670 Power transmission system 170a,670a Power transmission unit 170b,670b Power receiving unit M1,M2,M3 Mutual inductance S1,S2 Space Z ｐ , Z ｐｍ Impedance

Claims

1. A power transmission system comprising: a power transmitting unit having a driving circuit including a coil and configured to generate electromagnetic waves and radiate them from the coil; and a power receiving unit arranged between the power transmitting unit and the power receiving unit and separated from the dielectric plate by a dielectric plate, the power receiving unit having a resonator array structure formed by arranging a plurality of resonators that can resonate with the magnetic field component of the electromagnetic waves radiated from the power transmitting unit and whose size is smaller than the wavelength of the electromagnetic waves; wherein the coil and a first space between the dielectric plate on which the coil is arranged and a first surface of the resonator array structure are coupled by a first coupling due to a magnetic field, and a first load is connected in series with the first coupling; the coil and the resonator array structure are coupled by a second coupling due to the transmission of a magnetic field through the first space; and the resonator array structure and a second space in contact with a second surface of the resonator array structure opposite the first surface are coupled by a third coupling due to a magnetic field, and a second load is connected in series with the third coupling.

2. The power transmission system according to claim 1, wherein the second coupling is stronger than the first coupling.

3. The power transfer system according to claim 1 or 2, wherein the second coupling is a magnetic field resonance coupling.

4. The power transmission system according to claim 1 or 2, wherein the first coupling and the second coupling are coupled in parallel.

5. The power transmission system according to claim 1 or 2, wherein the power transmitting unit is arranged on the atmospheric space side outside a processing vessel that provides a processing space, the dielectric plate is a top plate of the processing vessel, and the power receiving unit is arranged inside the processing space so as to be spaced apart from the top plate.

6. The power transmission system according to claim 5, wherein the first load and the second load are plasmas.

7. The power transfer system according to claim 5, wherein the distance between the lower surface of the top plate and the first surface of the resonator array structure is less than 50 mm.

8. The power transfer system according to claim 5, wherein the resonator array structure has a through hole penetrating through the first surface and a second surface opposite to the first surface.

9. The power transfer system according to claim 1 or 2, wherein the resonator array structure is formed so that the magnetic permeability as a whole is negative.

10. The power transfer system according to claim 9, wherein the relative permeability is -0.

6.

11. The power transfer system of claim 1, wherein the first coupling is stronger than the second coupling.

12. The power transfer system according to claim 11, wherein the second coupling is a magnetic field resonance coupling.

13. The power transfer system according to claim 11 or 12, wherein the first coupling and the second coupling are coupled in parallel.

14. The power transmission system according to claim 11 or 12, wherein the power transmitting unit is arranged on the atmospheric space side outside a processing vessel that provides a processing space, the dielectric plate is a top plate of the processing vessel, and the power receiving unit is arranged inside the processing space so as to be spaced apart from the top plate.

15. The power transfer system of claim 14, wherein the first load and the second load are plasmas.

16. The power transfer system according to claim 14, wherein the distance between the lower surface of the top plate and the first surface of the resonator array structure is 50 mm or more.

17. The power transfer system according to claim 14, wherein the resonator array structure has a through hole penetrating through the first surface and a second surface opposite the first surface.

18. The power transfer system according to claim 11 or 12, wherein the resonator array structure is formed so that the magnetic permeability as a whole is negative.

19. The power transfer system of claim 18, wherein the relative permeability is −0.

6.

20. A power transmission method for a power transmission system comprising: a power transmission unit having a drive circuit including a coil and configured to generate and radiate electromagnetic waves from the coil; and a power receiving unit arranged between the power transmission unit and the power receiving unit via a dielectric plate and spaced apart from the dielectric plate, the power receiving unit comprising a resonator array structure formed by arranging a plurality of resonators capable of resonating with a magnetic field component of the electromagnetic waves radiated from the power transmission unit and having a size smaller than the wavelength of the electromagnetic waves, wherein the coil and a first space between the dielectric plate on which the coil is arranged and a first surface of the resonator array structure are coupled by a first coupling due to a magnetic field, and a first load is connected in series to the first coupling; the coil and the resonator array structure are coupled by a second coupling due to transmission of a magnetic field through the first space; and the resonator array structure and a second space in contact with a second surface of the resonator array structure opposite the first surface are coupled by a third coupling due to a magnetic field, and a second load is connected in series to the third coupling, a power transmission method comprising: controlling the drive circuit so that the second coupling is magnetic field resonance coupling;

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